I use speedplays on rollers, but when I started I just
wore sneakers so I could put my foot down quickly.
You'll learn just how quick you can get out of the pedals,
thats for sure.
There are alot of threads about learning rollers, search
keyword rollers.
www.kreitler.com has some good tips
for learning to ride rollers.
The thing that really helped me alot was learning to relax
on them, even if you ride off them, you're not going to go
anywhere thats a fallacy, you have no momentum to keep
you moving.
I started riding in a doorway, soon moved out into a room
(actually alongside a chest high counter) with a foot stool
to help with mounts/dismounts.
If you need more tips, let me know
Marty