I think you can get all you NEED via Sheldon Brown.....and some online spoke length calculator....

That said, I like getting new stuff, too. I built my first set of wheels last fall and got two books, both available via Amazon.

The Bicycle Wheel by Jobst Brandt

The Art of Wheelbuilding by Gerd Schraner

Think I got both of them for a total of $30. Complimentary (though occasionally contradictory, as I recall) information.