There are hundreds of books on the market that relate to web design and the disciplines within. It can be difficult to know where to start, especially if you are new to the field. If there's one book to start with, its this one, Designing with Web Standards, by Jeffery Zeldman. Now in its third edition, this is required reading for anyone involved in website design and creation. Start here.

Let's face it, all browsers are not created equal. Some are actually quite atrocious in their disregard for web standards. Unfortunately, some of those browsers are still in use today.. (you know who you are, IE6). Whether or not to support older browsers like IE6, whether to force visitors to upgrade or gracefully degrade their experience, this is a topic for another day. In any case, if you want to serve a special stylesheet for a specific browser, there are several methods to use.