I just started my 5 shammy group and have done the following

Deadmines @ 20/21 (must have healing stream totem)
Stockades @23
SFK @ 23/24
RFK @ 24

I'm running 4 elemental and 1 resto shammy who actually "tanks" for me. One thing that helped a TON was to go drop ~40g at the AH and get some reasonable gear for them. I increased mana 40% on the elementals and stam by about 25% on the resto.

My rythm usually is just this
Lightning Shield x5
Healing Stream Totems x5
Searing Totems x5
Pull with resto shammy using a shock (frost is nice)
When in range then Lightning Bolt x4, start hitting with Resto
If multiples come then I'll drop Stoneclaw Totem x5, these will get non focused mob attention and has 50% chance to stun.
Rinse and repeat Lightning Bolt as necessary with occaisional Shock x5
If Resto starts taking more dmg than healing totems can keep up with then self heal but keep the elementals killing.

I'm sure down the road I'll need to work some more ellegance into this, but hey, only been at it a few days.

GL!