How many baby clothes do I need?

Mrs.Mayhem

How many outfits do you think are needed for each 3-month stage?  What about newborn size?  I know I may not need newborn at all, but I'd like to be prepared for a week or so, just in case.

Also, will you be dressing your newborn in a onesie (no pants) most of the time, or do you plan to actually fully dress them from head to toe?

Finally, what are your favorite clothing stores / brands for basics?