If I remember correctly, there were three or four writtens, and they were just like all FAA, most anyway, writtens. The oral and pratical are actually given simultanously and is the easiest of all of the tests. In my opinion your nuts if you don't pay for and take the prep classes, especially when you go for your IA. After you have been an A&P for a while, your eligable for your IA. That's when you can do yourself the most good.
If you plan on really sticking with this airplane thing, your crazy not to get your A&P/IA. You might could get hangar space for free etc. You may also lose a friend or two that are trying to make a living out of being an A&P. I think you also might have a huge liability issue as well that I don't know how to handle. I'm sure there is insurance, but I don't know where and how much. I also don't know if you can protect yourself by forming some kind of company etc. , but I am interested if anyone knows.
I would put the A&P thing right behind getting your instrument ticket.