Gotta agree with Av8er. Don't worry too much about trying to get ahead on a lot of airplane specific stuff. Your company will give you the info you need and the CRJ is pretty simple overall.
Besides, any POH you might get, even from your soon-to-be company, will likely be outdated. At ASA they can't resist regular change for changes sake with our procedures and manuals, so it's a challenge to keep up, even for line pilots. You don't need to try to unlearn incorrect info on top of everything else you are introduced to in groundschool.
The cockpit layout could help though.