Start with "What you leave behind". Then watch "Move along home". Then watch "Caprica", but only the final two episodes. Then watch "V" in reverse order.
Seriously, I think Saxman said it right. Start at the beginning and at least watch the episodes people have suggested, but definitely watch the pilot.
I mean this is one of the best sci-fi series ever and you have a chance to experience it in full...
If you must, skip right to season four imo. That's when there was a definite change of pace. Season three was pretty meh overall.