I would suggest putting that big header image across the whole top and maybe writing the name over it in one of the corners in a flowing old style font. In my opinion 2 headers isnt really optimal, one or the other.
I like the big welcome sentence on the second page, but not the side menu. ive tried to use percentage values for things in the past but never really been happy with them id suggest specifiying pixel values.
Also i would advise testing your sites in a strict browser like Mozilla, i used to get annoyed when people said this all the time because of the percentage of users who use them... but if u develop with the strict browser then it will be fine automatically in non-strict browsers (IE), but alas it wont be the other way around.