Hi,
Shaman is a great class to duo with any other class, slows, has buffes, heals, cures, dots... etc.
But neither Bard nor Shaman is a DPS class, so if you start from scrath and don't twink any, you are going to find out 2 things at first:
1- Stuff takes quite a while to die.
2- Untill you get at least 3 dots, shaman gonna end up tanking.
Also, bards songs are in general pretty crappy without a mod.
My advice to you and your friend is to take your time doing the noob quests, the rewards and experience is decent. Stay in tutorial till like level 10, exp flies there and you get some items there with at least decent AC, 2 or 3 of them with a bit of STATs and maybe some HPs, and 1 or 2 with focus effects (mana preservation, haste...)
If one class choice has to be a bard, I would pick something else other than a shaman, maybe a necro, wiz or druid. If you want to tank mobs with bard, you are pretty screwed till higher levels because you need to have access to instrument mods, AAs, better weapons and equipment to even think about tanking any and, nonetheless, you are going to tank worst than any other class except silkies.
On the other hand, if one class has to be a shaman, I would get a class that complements shaman better, a tank class, SK, Pally or Warrior. A mage and a shaman might be interesting too.
Good luck.