Looking good; the design is crisp and clean. Will you be putting some pictures in?
The W3C icons say it all about the code ;-) (Doesn't it you give a nice warm, smug glow when the validator gives you the thumbs up?) Do get into the habit of clicking the icon each time you change something as you never know when a small typo might have introduced an error (it's on the Contact Me page). [I know that this is a good habit to get into because I failed to do it recently .... and discovered that it's embarrassing to have the "valid XHTML" logo on a page that doesn't quite validate :-( ]
I notice that you've gone for a width in ems. Did you try a percentage width? It grows and shrinks with the user's window so it is more flexible and preferred by accessibilty checkers.
Since you are using a style sheet you could have a go at CSS layout too. It can be a pain in the proverbial when it doesn't behave, and browsers all have their own little quirks to mess it up for you, but, again, accessibily checkers prefer it.
If you stick with the tables you need to give each one a summary (for people using assistive technology); if the table is layout only you just need summary="layout only".