I’ll use Wikitravel to get some basic ideas about a place, but when it comes to actual planning I go pick up the Lonely Planet guide. It may have started as a backpackers’ guide, but that only lives on in the “shoestring” series. The rest have plenty of suggestions for every budget, college student or middle-aged businessman.

Another issue I have with Wikitravel is there’s absolutely no review process for their hotel listings, and personally Tripadvisor gives me a headache (can’t stand the reviews on that site). LP’s lodging recommendations have always been spot-on for me.

Rick Steve’s is also good, I personally enjoy his the many self-guided walking tours he includes in his books and his method of prioritizing sites is useful when I’m only in a place for a day or two.

Note that I’ve only travelled extensively in Europe, so this may or may not apply to other parts of the world.