http://www.timwerx.net/home/index.htm
http://www.manythings.org/japanese/links/
http://www.japanesepod101.com/
http://www.guidetojapanese.org/learn/
http://www.polarcloud.com/rikaichan/
http://www.csse.monash.edu.au/~jwb/cgi-bin/wwwjdic.cgi?1C
I think all these are incredibly wonderful sites. I've been studying Japanese with varying degrees of seriousness for about 7 years and for the most part, I was self-taught. I did take 3 classes but I found they weren't incredibly helpful since I already knew just about everything they taught in the classes. I think with the right motivation and determination, you can definitely get very far with self-study. The hard part is keeping motivated! It's especially hard when you don't regularly speak it on a daily basis so you will need to find the motivation to keep learning. I have a few points of advice I would like to share with everyone:
-Always find some kind of activity that relates to Japanese. Be it translating for yourself or others, reading manga, listening to anime, listening to music, chatting online, writing blogs, etc. These activities help keep you grounded and connected with the language. The worst thing is to just stop doing things.
-Try not to get too caught up on the syntax of Japanese. Learning grammar and all that is fine and all that, but I feel the way they teach it in most places, including classrooms, isn't exactly the most efficient or effective way of actually LEARNING them. Kids learn through osmosis and endless trial and error. Do the same. As a kid, you didn't learn your native language through rigorous grammar study. You just kinda picked up on them. I suggest you try to do the same. How? Just keep making mistakes and hopefully a kind person will help point out your mistake. You learn, you live, and you move on to your next goal.
-Japanese is a rather hard language, especially for Westerners. Everything ranging from the words and pronunciation right down to how they think is just radically different. I personally think in order to effectively learn better, perhaps try to step into the mindset of a Japanese person. Of course, to do so 100% is impossible but I think getting into the right state of mind will help the osmosis process a little better. Learning the culture and traditions of Japanese people helps a lot with the language. After all, language is a part of culture.
-Find as many Japanese speaking friends as you can. Especially a good friend that's willing to help you out and won't be annoyed with your questions. Of course, you should try to find out the answer on your own before bugging them. =) In my case, I have a great friend who's fluent in Japanese, lives in Japan, and most important of all, is chill and doesn't get annoyed with my questions. He is a native English speaker and can articulate the INCREDIBLY SUBTLE nuances in Japanese that always eludes us learners. He understands that we all need help. I hope you all can find someone like that.
-Practice as much as you want. It helps to try and form sentences on your own. But it's also important, in my opinion, to mimic what you hear and keep it as a staple sentence in your repertoire. Just be sure to take note of all NUANCES in that sentence. For example, is it something said by only females or males? Is it someone said only to people you're familiar with? What kind of meaning does it carry? What situation would you use it in? These are important questions to ask whenever you're learning something new.
-Often times, help and resources are free. Interest in the Japanese language is very high so there's bound to be something that will suit you out there on the Internet. Spending money isn't necessary, but if you must, I do recommend the following:
Kodansha's Effective Usage Dictionary. This helps with words that seem similar but have different usages. My only gripe with this is that the example sentences are written in a weird romaji style, as opposed to kana and kanji.
Intermediate Japanese by Akira Miura & Naomi Hanaoka McGloin. This book is really for intermediate to advanced students. I like the layout and it's great for reading practice. Lots of vocabulary too.
Of course, these two books are really for the intermediate learners, but for beginners, I think web sites are enough.
Hope this all helps.