A free online resource to be aware of is the new language-learning social networking site Livemocha. Livemocha lets you choose a language to learn, progress through learning materials, practice speaking and writing with native speakers or others learning the language, and then give back by helping out other users trying to learn your own native language. Oh yes, and it's FREE. F-R-E-E. Nice! To learn more, check out their site walk-through. Two other similar services are iTalki and My Happy Planet, though neither one seems to have the user base or resources that Livemocha does.
There is also Mango Languages, which is subscription-based, but patrons can have a free trial with registration. For more info, check here.