With branches in London and Toronto and tales from all round the world, the Globetrotters Club is a good resource and sounding board for trips, tips and plans.
Shoestring Travel is organised strangely but has good feature articles, travel tips and a comprehensive list of travel-related Web sites.
Escape Artist is a massive resource for 'expatriates and freedom seekers'.
Worldwide Classroom's Library of International Programs lists schools and programs in almost 100 countries. You can find out how your prospective school fares at the 'ask the student' section.
Amerispan runs volunteer internships in several Spanish-speaking countries, and also has a Spanish-language program.
Studyabroad's World Wide List of Study Abroad Providers is a good place to start. Its experiential programs include internship and au pair listings as well as straight academic stuff.