With a hand held drill, I get the best results using old and dull general purpose drill bits. I've tried everything from diamond coated super sharp bits to the pointy wood bits and I find the really sharp ones tend to bite and take chunks out of the acrylic and crack it, whereas the dull ones generally make a nice hole as long as you don't wobble the drill too much. Of course, a piece of wood under, low rpms and not too much pressure are required.
For marking, I just use an awl, I generally don't drill pilot holes, but I guess you can, just don't drill them too deep.
If you got access to a drill press then it's much easier and sharp bits will be fine as you got so much more control.