From my friend who was in: they get some daily time, and all their email is monitored. I could send him mail, but it was through the prison's website, not a regular email.

I imagine the web surfing they can do is fairly limited, but I didn't ask.

I also found out that you can buy anything in prison, including a cell phone, or drugs. Ratting out the people who actually sell the stuff is a great way to get yourself killed.