I agree with C.J. 1000% Big Nick has 3 dvd's for lessons.. Beginner to Advanced and you really want to get the DVD 1.. Its for beginners learning Cajun style of playing. I have and used it and very good.. He really goes to length to explain whats going on..
It just so happens that I went through, read, and applied the little light blue book called "You Can Play Cajun Accordion "Designed For Beginners" just last night! It was given to me by a student of mine, I gave it away to another fellow accordion player because I kinda thought it was too far below my playing level. That little book has the basis typed in it for just about all I have posted her on The Cajun Accordion Discussion page. I wish I had really read it an applied it earlier in my now 28th year of playing accordion.
Yes, listen to them on how to pattern your fingers and let your fingers always set on the home keys using your pinky to play the bottom buttons and your index finger to reach up to the top buttons while searching for doubles. You really need them doubles about 50% of the time you're playing and the other 50% will go to quick little rolls, thrills, triplets, and junk that makes the sound Cajun. Label your accordion with the "cheap masking tape" just like the book tells you, or you can use my method of permanently marking the fingers/flappers with their push/pull notes. Mark the push notes closest to you and the pull notes farthest away from you. You want to mark both the push and pull notes toward the end of the fingers/flappers. And look at them as you play! You will get the sound, feel, placement, and the got dam notes delivered directly into your conscious every time you play a practiced song or a brand new song.
Your journey will be life long. Don't rush it! And listen to Cajun Music constantly. I mean go to sleep at night listening to it. Drink your coffee in the morning listening to it. We now have the technology for you to listen to as much Cajun Music as you can stomach. And read all of the writings of Greezy McGill if you want the inside scoop directly from a mad coonass.
A little analogy on finger placement on the home keys. Think of a beginner as a child who needs a home. A base foundation. The home keys of 5,6,7,8.
Think of all the available different positions (keys of play)that are available on any Cajun accordion as the neighbors houses in the neighborhood. Other than home base which to me is directly related to playing in one of the Primary keys of "G". The other houses in the neighborhood of the "C" accordion have addresses; and they are the keys of (C,D,F and A minor). So all of the addresses or keys of the "C" accordion are (C,D,F,G,A minor). A minor is only used for The Mardi Gras Song in most cases.
The child will remain at home base only visiting occasionally to the other homes in the neighborhood. The child will learn every aspect of his home base until he becomes bored with home base. When he becomes bored with home, he will remember his little adventures (reaches with the pinky and index finger to the top and bottom buttons. The child shall begin to visit these other homes more frequently and with more deliberate intent. He will begin to jump from home base to the neighboring home bases out of necessity. The movement will become natural and expected as long as he behaves himself at the neighbors home base.
Eventually the child will move out of home base and establish his very own home base (Style) but he will always remember home base and will revisit it as often as he needs to.
The home base addresses for all of these different keys of play are
Key of "C"...buttons 3 and 6 push.
key of "D"...buttons 3 and 7 pull.
Key of "F"...buttons 4 and 8 pull.
Key of "G"...buttons 5 and 8 push.
The songs played in these keys may not start in the listed keys, but they will surely end in the keys listed. Your job is to be able to jump around to these other home bases. Play the buttons listed above to establish yourself and the other people to the sound and feel of the key that the song is to be played in. When you get very familiar with each home base you shall begin to memorize all paths associated with them. Like you would memorize the road or path to and from the neighbors or cousin's house back to your home base. The finger patterns (paths) to each house are all different, yet they are in the same neighborhood. I hope you are able to decipher this wisdom in due time. Again, you have the rest of your life.
My two cents on working the bass side in with the treble side.
Learning the two hands separately will not get you there, not very soon. Your brain still has to learn to coordinate them together. Your hands are not naturally wired in your brain to do two different things at the same time. Our nervous system is wired symmetrically. You have to train yourself to break that.
What I found helped me is to slow the songs down SO SLOW, that your mind can begin to think of what each hand is supposed to be doing, and when. It will be really slow to get there, and won't be much fun.
As you start playing to that slow sound (I rely on hearing it in your head), with both hands, you can start to integrate it together into your head.
Again, it won't be fun. It will be work.
I would add that learning the treble side first, then slowing way down and adding the bass is the way I did it. Too much going on the treble side to memorize before trying to add the bass in the manner I described.