Nucs definitly give you a big head start. Think of a nuc as an already functioning hive (just smaller). Brood in all stages, nurse bees, field bees, and a queen who is their already accepted mother. Many beekeepers prefer packages because you don't know where the equipment and wax you are getting in a nuc has been. Has it been exposed to foulbrood, has it been treated with any chemicals that may still be in the wax, you never know?
Any apiery worth its salt should very willingly give you a history of medication and all the rest of this before you lay down the dollars for the nuc though.
Good luck with your bees and remember, have fun! :D