The offspring takes on 3 of its parents' characteristics. This is random, and sometimes it inherits the same stat from the mother and the father, meaning it only inherits two in total.
Um.
The Whismur family is one of the more versatile ones in the game, having both good Attack and Special Attack and a good range of physical and elemental attacks to choose from. There is no one good set for them, though Rest is reccomended.
It's one of the few that can learn Extrasensory (through breeding from Nuzleaf or Shiftry), but doesn't usually have the speed to gain any benefit from Extrasensory's Flinch. Can be teamed up with a Paralyser for good effect (Stomp also is useful for the same purpose).
Earthquake can be bred on, which is good (many final stage pokemon can only get it by TM as their earlier stages do not learn it). Ditto for Brick Break. Hyper Beam is a natural move.