There really is no step by step guide.

For myself I have been building websites for almost 15 years and PHP XML and javascript are all fairly well in hand. So as I began to make a custom solution for my guilds new web site (3rd one we have gone to) I was easily able to pick up on advanced techniques to incorporate them into some very original ideas.

Your best solution, if you have no coding experience for such an endeavor, is to go find a pre-made package. There are tons and many include the roster upload feature, plus they will have things like forums, event calendars and DKP tracking.