Blackshirt,
I am one of those 1st-timers as you may call us and can tell you with regard to hours that you can do as many as any other F/O.
In the last 10 months I've easily gotten about 600 hours, making that about 720 on average a year.
It appears that some other F/O's do a lot more, 80-90 a month, and others are on standby's most of the time, but even if this were to be true, lots of hours to play around in a 737.