I recommend the Non-Designer's Design Book too.

Also, I recommend Don't Make Me Think, by Steve Krug.

I'm a terrible designer, but have learned a few simple things from these books and other great designers.

First, here's what's most important:

- Copy (most important!) - Size/Shape/Position

Much further down:

- Font and colors

Second(paraphrased from Krug's book):

1. Does this site offer something of value that I want? 2. How hard is it to extract that value?