To pick up on Richelle's point, the colours are all over the place, no continuity at all and that makes it hard to read.
You need to set your paragraphs correctly, make sure the text is well set in blocks.
Perhaps the thing that really stood out to me was it looks cheap because of the cut and paste, even the donation tab is a cut and past, that screams cheap and tacky to be honest.
If you want people to have confidence in what the website is all about, you have to give the impression that you yourself know how to make money, and that should reflect in the website design.
Changing to a white background will solve your cut and past issues, and it will make it far more professional looking straight up. The top banner is just way too busy and despite the title of the site you have written there, it doesn't work at all.
Try to theme a banner, visit a site like www.istockphoto.com and search for money images and build a banner around the theme of your site. About 30 pounds and you can get a pay as you go royalty free licence for about 12 images, depending on the size you want of course.
From there you just need a basic graphics program and start playing with some designs.