Well 1st of all :o
i dont like the toooooooo bright green for the main content xD
try to make it darker to be able to watch the letter clearer without hurt my eyes xD
also the side menu i think that is toooooooo simple too :P try to add some buttons instead of letters
if u made a table there try to use align=right to make it close to the content
logo is cool except the S cause i think is under the logo and it make it a bit more invisible
i hope my comments will help you a bit :p