I think the hardest one to learn by yourself out of all three of these is Chinese because you need a native speaker to make sure your tones are correct (if you're tone deaf, learning to speak will be pretty much a nightmare). I think the only good work around I can think of is if you record yourself, listen, and correct yourself over and over until you've mastered the sounds and tones. My all time favorite Chinese <-> English dictionary is
http://www.nciku.com because you can use your mouse to draw in the characters instead of having to look them up by radicals and they have a wealth of example sentences. For class we use Chinesepod.com once in a while and you can get a lot of access to the content just using a free account, there's no need to pay for one. For the beginning and intermediate levels, I recommend the Integrated Chinese series. I don't recommend buying the character workbooks at all because you can just write the characters down on a regular sheet of paper to practice. If you need workbook answers, just message me because I still have all my old homework.
For Japanese I highly recommend the Genki series of textbooks for beginning and intermediate learners. You can find direct download links to the entire textbook, workbook, CD, and answer key set on the first page of the search results on google. There's a new Second edition version that just came out and when I compared the books there weren't enough changes to merit actually buying the second edition, 95% of the text and vocabulary are still the same. The only differences are that some of the older vocab words from the 90's like Cassette player have been replaced with more modern words like Personal computer and some sentences have been reworded in the reading texts (but the meanings are still the same).
Don't buy the Yookoso! textbooks, they are terrible. My teacher thumbed through the book and there were a lot of times where vocab words/grammar points that aren't explained anywhere in the book were used in the reading texts.
For grammar help I use Tae Kim's guide (
http://www.guidetojapanese.org/), and I recommend
http://www.jisho.com because it's my all time favorite dictionary and it has a good number of example sentences.
http://ejje.weblio.jp/ is alright for translation help also if you're really stuck, and if you honestly can't find a word in the English -> Japanese dictionaries, your best bet is to just go to a real japanese dictionary like
http://dictionary.goo.ne.jp/ and try to read the definition or google translate the definition. When you need to look up kanji, just go to the nciku dictionary I linked above and manually draw it, then copy paste the character.
For
all of the languages, any time you need to translate a place, name, or event, all you have to do is go to Wikipedia, look up whatever you want, then go to the side bar on the left and find the japanese/chinese/korean version of the article and the title of the article (the person/place/event) will be translated into the language you're looking for. I do this all the time and 90% of the time it works, the other 10% is when the article hasn't been written in another language yet.
Edited by Kannade, 02 March 2013 - 07:15 AM.