We have been trading Eurex for years and the data seems pretty stable. I think when you use systems like IB and PATS with so many users there could be a problem.
You can order a book through Amazon. I just took it. Take the practise test a few times and you should have no problems. There are some wrong answers though.
Kwik Trading is out of Chicago. A nice group of guys. I am not sure what software they are using but everytime I talk to them they are very helpful. I think they are a GIB of Alaron.