If you've attended one of my classes you know that I recommend everyone get a copy of Ted Pattison's and Dan Larson's Inside Windows SharePoint Services 3.0 by MSPRESS. This is my favorite book on SharePoint v3 and is number one on my "AC's Best Damn SharePoint Books" list.
If you can't read the whole thing, you have to at least read chapters 2 on "SharePoint Architecture" & 3 on "Pages & Design". Well, thankfully for those of you who hadn't read it yet you can now! These two excerpts have been posted on MSDN for your viewing pleasure!