Honestly, i'd read Palmer's book. start with the online version if you haven't already: www.howtobrew.com
The printed book does indeed explain the different types of base malt, specialty malts, and hop varieties, as well as how different yeast strains affect beer.
its a well written book that does get in depth but does not feel like you're reading a text book.
here's a good, simplified link, about various grains: http://hbd.org/brewery/library/Malt101.html
now, if you're only doign extract brews, there's less to learn, since you're not messing with base malts, only specialty grains for steeping to achieve some flavor and color.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10