My Shaman/Paladin is at 56 now. They are a blast to play, and work well together

Right now I am doing Retribution for my pally, and Enchantment for my shaman. Between the totems, and auras they buff each other very well. Usually I just drop Windfury, but if there are several mobs I can pull to one location I usually drop the Strength totem, and the Mana totem. I find that mana can be a bit of a problem, but if you keep Blessing of Wisdom on both you are fine. If mana is still an issue, slow down your casting a bit, use Seal of Wisdom, and Shamanistic Rage. This will bring you right back. Both characters have a rez, which is awesome. Shaman has wipe recovery (I guess pally does too, I just never use).

I think the toughest thing is playing two melee characters. Typically my shaman is following my paladin, so if you run through the mob the shaman will start attacking. This is nice because it give the pally a chance to gain agro. I try to keep agro on my pally, then heal with my shaman as needed. I also have bound my paladin to WASD, and my shaman to my arrow keys. This way I can reposition each individually during a fight if needed.

Let me know if you have any questions about setup, I'd be glad to help.