Some hints for the upper levels:
http://www.ethereal.com
http://www.google.ca/search?q=baconian+encryption
On level 7, the only hint I will give you is you have to spoof the browser. Forget level 8 + 9, they are tough as hell.
BTW, try these noobs
http://www.slyfx.com/
http://www.caesum.com/
http://arcanum.co.nz/
http://www.hackquest.com/