Most color wheels will help you pick three colors, but this isn't really necessary in basic sites. One of the things I've used to overcome this is to just use two colors. Even better is to just stick to the grey scale.
From there, learn a bit about typography. Typography can make a huge difference on whether a site looks great or looks like utter crap. I've seen a few sites that kept color choice really simply without a lot of fancy graphics that truly looked beautiful.
Another thing that will definitely help is practice. Do a couple practice mockups and breakdowns. You can follow along to a tutorial like http://is.gd/Lpx4 or just wing it. The first design I did was a royal pain, but by the second or third design, the process became much more natural and a lot easier. Each subsequent design has gone a lot smoother as well, and I can only attribute this to practice and reading about design.
From there, learn a bit about typography. Typography can make a huge difference on whether a site looks great or looks like utter crap. I've seen a few sites that kept color choice really simply without a lot of fancy graphics that truly looked beautiful.
Another thing that will definitely help is practice. Do a couple practice mockups and breakdowns. You can follow along to a tutorial like http://is.gd/Lpx4 or just wing it. The first design I did was a royal pain, but by the second or third design, the process became much more natural and a lot easier. Each subsequent design has gone a lot smoother as well, and I can only attribute this to practice and reading about design.