When I know nothing of a country, I check our travel packages from travel companies to get a general idea of the ''must see places'' that are usually in a tourist's itinerary. I am also a fan of travel guide books like Frommers or The Routard. Once you are in Europe there are many airlines/train companies that connect pretty much throughout all Euro Zone countries. Still, the main focus should be on your time and budget. Don't forget to check the documentation needed and insurance. It's always good to be prepared for the unknown.
The biggest tip I give you is do it now and don't wait a second more. Start planning and go for it!
I leave you with several links that may be useful:
A country by country guide that will surely make you inspired : Guide to Europe CNN Traveler
Getting in the mood? : Europe awaits
A straightforward website with useful tourist info: Rick Steeves tips
The key is to pack light and be practical Pack light for Europe