Hey Mickledm. Congrats on getting a chance to fly the "Fat Astra". I've been lucky to have flown them on and off for nearly the last 10 years and it's fun. Over the years, the plane has earned a reputation; some good, some bad, some undeserved and some deserved. But so have some of us pilots. It's best to form your own opinion of the aircraft while at the same time learning from those that have scared themselves a time or two in the past.
The link provided above is good. Copied from the AFM, it is mostly up-to-date but is only a brief summary of the systems.
As for training, I've only gone to CAE (Simuflite) once for recurrent training back when they first started the G200 program. FlightSafety has the exclusive rights to the G200 from Gulfstream so CAE had to borrow an actual G200, hook up computers and cameras to the plane and fly to it to get any data to program the simulator. The only manuals for the plane they could get was from the original Galaxy (Google that story to learn about the turbulent past this plane has endured) and hadn't been updated to include the many changes to the systems, procedures and limitations that had occurred since the name change to the G200. Hopefully CAE has acquired newer manuals and have managed to improve the course since I took it.