The most basic composition has long been the 4x shaman and a paladin group. 5x balance druids, with two of them dual specced to tank and heal is also popular, although with the moonkin healing glyph for levelling content you might be able to get away with 4x balance + 1 feral even in dungeons.

If you're willing to spend the money I'd do 5 for a month or two, you're probably going to have a rough time with 3 if you want to do dungeons to level and have to pug the other two (as a new boxer).