first impressions are i would put a good background and a new logo, if you are teaching people to use photoshop, it would be good to show it in your logo? one more thing is you should change the adsense with images along side i dont think its allowed even though it says sponsered link?
Looks great, its a launchable site. It's great and i don't really think its nessesary to make it look better although you may think it needs a touch up