Learning the theory of how to potty train a puppy is quick and easy - the hard point comes with being patient, consistent and sticking to your new puppies training schedule. Not to mention trying to get your puppy to acknowledge there even is a schedule.
There are so many books, websites and television shows all eager to share their opinion on dog training and how to potty train a puppy and many of them will tell you completely different things. I cant say I know best but I can tell you I have a lot of experience potty training puppies.
The first thing you'll want to know is how log it will take. It can depend largely on the individual dog and the person doing the training. With a naturally well behaved dog and an experienced trainer you could be looking at days to weeks. On the reverse it could be weeks to months. If it starts to get beyond three or four months you should consult with a vet and perhaps check for medical bladder issues.
The key to potty training a puppy is practice and commands. Dogs, like many humans, learn through repetition. By repeatedly taking your puppy outside and praising them when they urinate and scolding them when do it inside you're puppy will learn. That's the bread and butter basics of how to potty train a puppy.
You should teach by praise and reward not fear and punishment. The puppy should learn to want to urinate outside, not do so out of fear of you. If you catch your puppy urinating indoors scold thrum (with a loud command such as bad!) and move them outside quickly. If they continue to urinate praise them and return indoors.
If you return home to find the puppy has urinated while you were out then you can't really punish them for it. You may notice your puppy hanging his head or tail but they can make the link between whatever happens to you outside and them being punished. This will not make your puppy comfortable with you being outdoors and he or shy will act out. Instead avoid any praise and clean the mess up while ignoring the puppy for a while. When you do return attention take them outdoors.
When it comes to learning how to potty train a puppy training the puppy is the easy part - training yourself is where it gets tricky.