American Gunsmithing Institute, they sell armorer's manuals in DVD it shows you in detail how to identify, disasemble, reasemble, what to look for when you have a problem. printable scematic too
It is a comlicated beast and when it works it is great, but get a bad one and if you cant fix it it will cost more than its worth to fix. I have too much time invested to turn back now, my advice is you better realy want one before you get into it.