The main trouble for the buddying accordionist is that good material online is really scarce. Pretty much the only free tutorial i have found on the net is this 4 page instruction on how to play lady of spain. It won't get you very far but hey, its a start.
The other problem you will face is that learning to play from a book is hard even if you know how to read sheet music. It is very important to get the left hand technique right from the beginning since bad technique will make it very hard to play the right hand at the same time and will slow your learning speed conciderably.
The best thing is of course to learn from a real teacher. Good accordion teachers are however not that easy to find in the 21th centhury and expect to pay $30 - $50 for a 20 minute lesson.
If you aren't able to get a teacher the next best thing is to get some kind of video. Myself i learned from Enzo Giribaldi's Downloadable Accordion lessons wich i think are pretty good since you get video with close up shots on how you should play both hands. The webpage looks pretty amateurish but the material is solid. It also teaches you to read basic sheet music so you can graduate to books.
Another option is to get a VHS or DVD but most i have found seems to be geared for players who know the basics and music theory and are therefore not too useful for the beginner.
After you have the fundamentals down either by lessons or training by yourself I recommend buying a beginners book like Mel Bay's You Can Teach Yourself Accordion
. This book includes a CD with songs. If you buy another book make sure you get one that includes a CD otherwise it will be hard to get anything out it on the songs you dont know. The advantage with books is that you will get many songs to play, the disadvantage is that you will be left on your own to figure out lots of things. After playing through your beginners book i cant give you more recommendations because its now up to you to decide what you want to play. Hopefully you should be able to just grab any piece of sheet music and play it in a few tries. Or why not make you own compositions!
