Okay, I want to know how to code a wordpress theme of my own. I'm guessing I need to know php and css, right? Does anyone have any suggestions of books that I could study to teach myself the basics of this? I know I don't necessarily need to "learn it all" to make a theme, as I can cobble it together from defaults... but I want to at least have a basic idea of what it is that these defaults are doing.
Any suggestions are appreciated, thanks.