I agree with Levi and Typo. To be honest the effects used aren't very professional, quite basic, couple of clicks in Photoshop sort of thing. You need to bring a theme into it as at the moment the colours look they have been picked out of a hat. I think you need to think of each banner as a separate entity as at the moment it looks as if you have just thrown them all together. Spend a bit more time developing each banner and think of how each can link to another with a similar style but at the same keeping it simple like Levi said.
So have another go at the logo, incorporate the logo into the site using the colours and style etc and I think you will end up on the right track.
banners are looking better. I'm not too sure about the dark background though, personally I feel it's not very pleasing on the eye, quite dreary, perhaps try a lighter colour and see how it affects the rest of the site.