Check out
http://www.eurotrip.com
There is quite a bit of information - from hostel reviews, to a packing list (for a month, I think), flight and train info. Its a good place to check out.
Also - I agree - you should be checking out as many guidebooks and travel videos as possible so you get a sense for what you will want to do.
Also check out Budget Travel - they have tips for city-savers such as museum passes, etc. for some of the larger cities such as Paris, London, Amsterdam, etc.
Here's another website you can check out. Cecilia has a ton of information on a plethora of subjects. I used quite a bit of it for my recent trip.
http://www.xs4all.nl/~cile/
Also - if you haven't seen it, the "Smart Traveler's Passport" has all kinds of tips - from packing tips, to hotel tips, to cruise info - all from travelers. If you can find it at the library, its worth a read. I try to read it before every vacation - I often forget how much I've forgotten!
Good luck!!! Keep us p