I went back to school to take pre-requ's as well.. So I totally understand your confusion concerning which classes to take. The way I tackled finding out per-requ's was by deciding what schools appealed to me (and where I would eventually apply). I find that UF has a great list of classes that are pretty much across the board as far as per-requisite classes. But there are so many other classes to consider that aren't on that list (I.e. anatomy, physiology, cell biology, etc.
If you are serious about returning to school and taking pre-requ classes, don't stick with the bare minimum - you are going up against applicants who have taken all of those classes and then some.
I hope this helps! Good luck!!