The Lonely Planet has a series of books, I'm sure there's a Southeast Asia book, and I know there's a Europe book - -head to your local Barnes and Noble and read up on both
Google is our friend...
So you wanna backpack thru europe
BAckpacking Travel Tips
Answers to Safety with regards to backpacking thru Asia - -their suggestion to check the state departments travel advisory site is probably a good one
Backpacking thru Asia