I'll just add what it says in my signature line about a paradigm shift but you have the added advantage of never having thought in rows before. Think about what you want to do to a column instead of what you want to do to a row and you'll be way ahead of the game. Also, look for the book on being an "Accidental DBA". That'll help a bit with the systems side of the house. Make sure that you have "Books Online" (the "help" system for SQL Server) loaded on your machine because it's easier to use than the Internet version (especially the INDEX tab). The first thing I always did when I studied a new computer language was to learn the basics and then study all the intrinsic functions. They make life a whole lot easier.

I'll also say that learning about indexes on tables is one of the most important things. Anything by Gail Shaw or Kimberly Tripp on that subject is well worth a read.