My advice would be to go with 4 shammy and a paladin unless you know for sure that you want to have a dedicated healer at all times, then you could choose to level druid, priest or shaman to heal. I guess another option is 4 shamans and a druid. Then you can have them all specced for ranged dps if you wanted to go to AV, but you also have a tank, healer and 3 dps for instancing.

As far as builds go id suggest just playing around with the in game talent calculator which can be turned on in the interface menu. Most must have talents should be pretty obvious to you. Once you get to 80 then look at researching the optimal builds if you are into min/maxing