This is a thread of resources to learn languages that I will try to compile, including books, websites, videos, etc. For now they will be organized by type of source, and if the source is tailored for a specific language, it will be a subset of the source type. If you have something you'd like to see here, PM me and I'll check it out.
WEBSITES:
http://www.ielanguages.com - IE Languages, basic to advanced lessons in French (I-VII!), Spanish (I-V), Italian (I-III), and German (I-V), as well as guides for several other languages, and even guides to learn two languages at once.
http://en.wiktionary.org/ - The English Wiktionary, has lots of words and their declensions, conjugations, entomologies, etc. Very handy.
http://www.omniglot.com - Omniglot, provides information about languages and writing systems of the world, current and past. Very informational and great for introduction to a language.
http://www.italki.com/ - iTalki, the social network of language learning. Here you can find friends and language buddies to help you learn, and you can also look at the different lessons that teachers have on these (costing $.10) and different guides written by users.
http://www.101languages.net/ - 101 Languages.net. Covers the basics of several languages (around 30-40 at last count, not quite 101). DEFINITELY not for the linguist or one actually looking to learn the languages, but it will help you pick up travel phrases and interesting tidbits (e.g. colors, numbers, days of the week).
http://www.quizlet.com/ - Quizlet, primary and secondary school teachers often put flash cards and quizzes here for their language classes, and the flashcards are open for anyone to use. Just look up your language and study away.
http://www.about.com/ - While you may kind of roll your eyes at this one, it's actually not that bad. The French section is great, which I'm currently using. Definitely worth at least checking out.
http://www.filestube.com/ - FilesTube, searches upload websites like MegaUpload, RapidShare, etc. You can find a ton of stuff on here.
http://www.elanguageschool.net/ - eLanguageSchool - Awesome free resource, but the front page comes up miscoded for me and ends up as a bunch of scrambled characters. Try entering the different languages through Google Search, it's worth it. If you have a language in mind to search, it offers Japanese, Spanish, Portuguese, French, Italian, Dutch, Korean, Chinese, and Russian.
http://idiomas.astalaweb.com/ - Idiomas.Astalaweb - Completely in Spanish, but it has free resources for almost every major language imaginable, as well as programming languages. Worth a shot if you know Spanish.
Germanhttp://www.deutsch-lernen.com/ - Deutsch Lernen - Seems to be a very solid website, includes exercises and the like.
Greekhttp://www.kypros.org/LearnGreek/ - LearnGreek on Kypros.org - Free course for learning Greek. My friend is using it and he really likes it. You'll need to register, but it's free of charge.
http://www.typegreek.com - Type Greek, added thanks to Anal Probe Deluxe, allows you to type in Greek without installing Greek fonts. However, it does lack diacritics, so buyer beware on that one (although it's free).
Japanesewww.guidetojapanese.org - Tae Kim's Guide To Japanese, a pretty decent breakdown for learning Japanese grammar.
http://www.thejapanesepage.com - TheJapanesePage, great resource for learning Japanese, grammar lessons and the works.
Latinhttp://schola.ning.com/ - Schola, Latin forum and education portal. If you want Latin immersion, this is the place to go.
http://mysite.du.edu/~etuttle/classics/latin/learnlat.htm - Latin for Mountain Men, a short course in Latin. A fairly barebones guide to the language, but it's free.
Oscanhttp://indoeuro.bizland.com/tree/ital/oscan.html - Oscan Language Resources, the best website to learn about the ancient Italic language, includes concise dictionary. Definitely a fascinating visit.
Romanianhttp://cnt.dnt.md/romint/undp/nivel1.php - Departamentul Relatii Interetnice, Romanian lessons from Departamentul Relatii Interetnice, includes three levels, posted by the government of Moldova. Warning: in Romanian.
www.romanianlessons.com - Romanian Lessons.com. It's really not great, but it has the basics, and is unfortunately the best thing out there on the interwebs for the time being.
Spanishhttp://www.studyspanish.com/ - StudySpanish.com, a great website for learning Spanish, breaks down things pretty effectively.
BOOKS AND PDFs:
http://thepiratebay.org/torrent/4871363/Language_Textbooks_-_various_languages_%2875_books%29 - Torrent: Language Books, has
75 different language books over: Arabic, Cantonese, Catalan, Chinese, Croatian, Czech, Danish, Dutch, Estonian, Finnish, French, German, Georgian, Greek, Hebrew, Icelandic, Irish, Japanese, Norwegian, Polish, Portuguese, Romanian, Russian, Scottish, Serbian, Spanish, Swahili, Swedish, Tamil, Thai, Turkish, and Yoruba. An all you can eat buffet.
http://en.wikibooks.org/ - Wikibooks, has good stuff over a couple languages, and is open source if you feel guilty about stealing books.
Frenchhttp://www.dudziak.com/french_verbs.pdf - 681 Most Common French Verbs, long and compact list in a tiny pdf file, with highlighting for 100 most common verbs, irregular verbs, and verbs showing movement and change.
Romanianhttp://www.seelrc.org:8080/grammar/pdf/stand_alone_romanian.pdf - Stand Alone Romanian, a detailed breakdown of Romanian grammar.
SOFTWARE:Rosetta Stone Ultimate 2007. Levels 1-2 of 26 languages. I've heard you may need to burn this to a DVD for it to work correctly, but I have also heard it runs fine in an .iso mounter like MagicDisc.
Japanesehttp://web.uvic.ca/kanji-gold/ - Kanji Gold, awesome software to learn kanji, has upwards of
6,000 of them, treated like flashcards.
VIDEOS:
http://www.youtube.com/user/Glossika - Glossika YouTube - The YouTube channel of the INCREDIBLE linguist and polyglot Mike Cambell. Definitely worth a visit!
Spanishhttp://www.youtube.com/watch?v=RuSqTj9ZP2 - An excellent from Professor Jason over the Passive Voice in Spanish. This guy makes excellent videos, everything clicks instantly.
http://www.youtube.com/watch?v=qu7aFlCmRuU - Another excellent video from Professor Jason over forming the Present Subjunctive. He also has a video on when to use the subjunctive.
AUDIO AND PODCASTS
Frenchhttp://www.dailyfrenchpod.com/wordpress/archive-podcast/ - DailyFrenchPod, the podcast I'm using to learn French, not bad if you have a decent level of understanding. The podcasts are free, but the rest of the site is not, unfortunately.
Norwegianhttp://thepiratebay.org/torrent/4917202/Pimsleur_Norwegian_Comprehensive_Units_1-30 - Pimsleur Norwegian, units 1-30.
Russianhttp://isohunt.com/lite/files/154553421/pimsleur%20russian - Pimsleur Russian, added thanks to da teacha. Lessons 1-8.
OTHERShttp://www.freelanguagecourses.com/language/russian/princeton-russian-course-51/ - The Princeton Russian Course. 1.5 GBs of material, from audio to pdfs. Thanks goes again to da teacha for this one. You are required to email the admin with some personal details (where you live/what you do), however.
BLOGS AND INTERESTING WEBSITES
http://www.fluentin3months.com/ - Fluent In 3 Months - Blog of Irish polyglot extraordinaire Benny Lewis. He's the author of the Language Hacking Guide, and he has a lot of good tips and stories in here.
http://foreignlanguageexpertise.com/index.html - Foreign Language Expertise, the blog and website of professor Alexander Arguelles. He claims to be able to read in over 20 languages well (but he doesn't make any mention about speaking). An extraordinary man indeed.
http://www.utexas.edu/cola/centers/lrc/ - University of Texas at Austin, Linguistics Research Center. A plethora of information about the Proto-Indo-Europeans and their relationships.
http://www.youswear.com/ - YouSwear.com - Curses, swears, and insults in almost every language imaginable. Have fun with this one!
Comments
I have Spanish (1-3), Levantine Arabic (1-3) and MSA (1-3).
Spanish & Latin American children's books
More kid's books
Translator, better than some others I've used
Elementary Spanish book with glossary
Pimsleur torrent
Michel Thomas torrent
Also despite the necro-bump, I can attest to the Michel Thomas language learning in the post above mine by Meloncholy. Just try not to get wound up by the fact the old fucker is hitting on the girl the whole recording. I listen to it at work.