Lonely Planet - Check out the Thorn Tree, a message board with just about everything you need to know about travel.
Hostels.com - Online booking site for hostelling worldwide.
Matador Trips - Great articles about all kinds of travel. You can find advice on Paris department stores and swimming holes in southwest Cambodia. Pretty good for adventurous travelers as well as those just starting out. Comments on articles are always diverse and interesting.
Atlas Obscura - Ridiculously entertaining and more than a little quirky, this website has everything you never knew you wanted to know about the world.
Le Blog Laura - An amazing blog from a writer whose worldwide meanderings are endlessly fascinating.
Solo Friendly - If you've ever traveled on your own or want to take a trip by yourself, check out this blog from a woman who proves you don't have to be scared of a table for one.
Jason's Travels - Jason reps Colorado hard but also has a great collection of travel information, especially travel book and product reviews.