I am by know means an expert but i will tell you what I think!
The layout is good. Everything is well organized and you dont fall victim to the commma trap of having to much stuff! I will offer a few suggestions to improve upon, but overall I think you should keep the layout as is.
keeping what i just said in mind i think you need to inhance your graphics, (but dont over do it). As of now the site is a bit too plane.
1. Change your header, It is kinda boaring right now and looks "old". It does not need to be anything extravagant, just somthing with more modern feel.
2.THe only formating on your navigation is that you took away the text-decoration then added it back for the roll over. I would try and make this part of the site more appealing as well.
3. Your welcome message is a bit to long it totaly put me off reading it and as a result i still don't know what your site does. if possible try to shorten this message. also add some visual cues that will let your audiance understand what the site is about quickley.
On second thought it may not even be the length that put me off reading it, The basic style of black text on white also did not help as my mind was thinking "boaring".
4.Consider adding some shape, a few curved boxes can go a long way.
hope this gives you some ideas