How long it will take you to house train your dog depends on your dedication to the training process and your puppy's maturity and learning rate.
Things you will need to housetrain your puppy are a properly fitted crate, a collar and leash, some treats, and time and patience.
You also need to pick a spot for your puppy to go potty. Using the same spot each time will help the puppy recognize that this is where he should go, and the smell from going there other times will help him go potty faster when you take him out.
I don't recommend using doggie litter boxes or those puppy pads. If you want your dog to always go potty in the house fine, then use this article to teach them to go there. But don't complain to me when your dog starts going other places in the house. Dogs often times cannot tell the difference between a puppy pad and your expensive rug. All they know is its ok to go potty in the house so any area with a roof is fair game for elimination. Also trying to paper train a dog and then trying to switch the dog to going outside is counterproductive and confusing for the dog. Doing this will only slow the training down. So forget the puppy pads and start teaching your dog to go outside from day one. If you have already been using them throw them out and start all over from the beginning, but keep mind the process may take a little longer the second time around since once your dog has bad habits they are hard to break. Its much easier to prevent them than to correct them later.
When looking for a crate you want one that is big enough for your dog to stand up, turn around and lay down. You don't want it so big that he can lay in one end and use the other end as a bathroom. If he can do this trust me he will. There are all kinds of different styles of crates: the two most common are wire and plastic. But they come in mesh, wicker, all sorts of different materials now. I would recommend choosing either a wire or plastic one, especially for puppies that like to chew.
Next you will need to introduce your puppy to its crate. Just sticking the puppy in there without a positive introduction can be very stressful for the pup. I like to bring a new puppy home on a day off, and try to pick it up as soon as possible in the morning. This way I have all day to introduce the puppy to the crate so that by bedtime the puppy will feel pretty comfortable with its crate and shouldn't fuss to much.
Start by showing the puppy the crate and let him explore it. Next show your puppy a treat and then toss it inside. When your puppy goes in to get the treat praise him excitedly. Repeat this a few times and then end this session. If your pup won't go all the way in the crate to get the treat try throwing it closer to the door, or even outside the door and then gradually toss it farther back, until the pup goes all the way in.
After an hour or two have another session with crate. If your pup went all the way in the last time start there, if not start at the point you left off. After a couple times of going in the crate and coming right back out you can shut the door. But let the pup out after a second or two. Repeat this gradually increasing the amount of time the pup is in the crate. If you do this several times the first day by the time your ready for bed your pup should be pretty comfortable with the crate. I also like to repeat this process for a day or two after the pup comes home.
Also remember that whenever your dog is crated you need to remove any type of collar, even a buckle collar can catch on a crate and strangle a dog.
Now that you have your crate set up and your pup introduced to it you need to put your puppy on a feeding schedule. Puppies 8 wks to 6 months should be given three meals a day. After six months this can be cut down to 2 meals. Free-feeding (having food available all the time) is not recommended. It can lead to obesity and makes it harder to housetrain your puppy. Another disadvantage to this feeding method is that it will be harder for you tell if your dog is off food which can be a sign of illness. Feeding on a schedule allows you to predict when your puppy will need to go out. If you know when it went in you can predict when it will come out. You will want to divide your dog's full daily amount into three smaller meals. Give him the food and after twenty minutes take away the bowl whether there is food in it or not. Dogs will generally consume all they want in twenty minutes. Take your puppy to his potty spot about 15-20 minutes after he has finished eating. Repeat the go potty command while you are waiting for him to go. When he starts to go tell him good boy go potty, and when he has finished give him a treat and make a big fuss over him.
I'd also like to tell you how to tell if your puppy is getting to much or to little food. The recommendations on dog food bags are just a starting point. Start with that amount and then watch to see if your dog needs more or less. The way to tell is to do a rib check. You shouldn't be able to see the ribs, if you can add more food. You should be able to easily feel the ribs under a thin layer of fat, if you have trouble feeling the ribs, cut back the amount of food.
In addition to having to go out after meals your puppy will also need to go potty after he wakes up from a nap, after playing, and first thing in the morning and before bed. Signs that your puppy needs to go out: are restlessness and circling an area while sniffing. If your puppy does these things it's a safe bet to take him out. Remember though that individual dogs have their own signs of needing to go to the bathroom and you will soon pick up on these signals as well.
When you are out for potty breaks you should stand still, if he wants to play ignore him. You want him to know that it is time to go to the bathroom not time to play. If you allow him to play before he goes to the bathroom he may start to hold out on you to extend his playtime. Once he has gone to the bathroom however you can play all you want. Stay outside with your dog for about 10 minutes to wait for him to go, if he doesn't go in ten minutes just pick him up and carry him back inside matter-of-factly. No treats or playtime on the way in. When you get back into the house he will either need to be crated or watched like a hawk. Try again in ten minutes. Repeat until he goes.
Another mistake a lot of people make when they bring their new puppy home is to allow him free run of the place. This will only hurt your training and will also cause your dog to get into a lot of trouble. Young puppies need to be watched. When your puppy can't be watched he should be in his crate. This way he can't make a mistake or get into trouble.
Accidents:
The only time you can punish your puppy for having an accident in the house is if you catch him in the act. Even then it's less of a punishment and more of a redirection. If you see your puppy going to the bathroom in the house, startle him with a sharp NO and take him outside to finish the job. When he finishes outside, give him a treat and lots of praise. Back inside the house clean up the mess and use an enzymatic cleaner (such as OUT or Nature's Miracle) to remove all traces of the mess so he won't be tempted to use the same spot. Most carpet cleaners will leave traces of the mess that you can't see or smell, but your pet can.
If you find a mess after the fact, well to bad that one is your fault, you should have been watching the puppy. Simply clean it up and try to watch more carefully. If you try to scold your pup after the fact he will have no idea what you are mad about and will be confused and may even become scared of you. NEVER, NEVER rub your dogs nose in urine or feces. It is not only disgusting but it also has no training value what so ever. Hitting your dog with anything including a rolled up newspaper is also unacceptable.
Young puppies may need to use the bathroom during the night, so I advise putting the crate in your bedroom. This way if the puppy sounds restless you can take him to the bathroom. This will also make your puppy feel more secure because he is close to you. If you do need to take your puppy out in the middle of the night make sure you allow him to go to the bathroom only. No playtime for these outings. Still give him a treat and praise, but do so in a quieter manner than you would during the day. This way you won't get him all riled up the middle of night. Remember if you let him get away with playing in the middle of the night he will begin to expect it, and you don't want that. How long night time outings will last depends on the age of your puppy, and how fast his bladder matures.
It also helps to have his last meal of the day at least two hours before bed and take away his water an hour before bed. You don't want to put it in the crate with him, it would be unfair to the puppy to expect him to have a supply of water and then not have to go to the bathroom all night long. The only thing that should be in your dog's crate are a chew toy and maybe a doggie blanket. Although some pups will urinate on absorbant materials that are in their crate, if yours does remove it. Also if you see that your puppy is chewing on his blanket it should be removed. If the puppy ingests part of the blanket it could cause an intestinal blockage. If that happens emergency surgery is needed to remove the blanket from the intestines.
I know this sounds like a lot of work but that is what puppies are. They are also a lot of fun and that should make up for the work part of having a puppy. And just keep in mind that one day soon you will have a beautiful dog who is housetrained and is a joy to have around.