Well my two cents on once you hit 80 is to gear your tank. I just hit 80 a little over a week ago with my second team and I went straight to heroics and my real issue that slowed things down was my tank and not being able to chain pull multiple mobs. I spent the weekend doing LFD and last night got my last piece of badge gear, I went from 2500 gs to 4700 gs in about 4 days of 3 - 4 hrs a day running random heroics. Tanks and healers will both get back to back runs. Now that my tank is geared I can run a lot of the heroics with very little healing and so this gives you more of a chance to allow your healer to gear without the pressure of healing the tank.
My shammies (3 in this team) all are around 2.5k gs and they still can kill multiple mobs really fast due to chain lightning.
I also agree to level one team at a time and gear them, otherwise it will burn you out leveling all teams. Once the first team is geared and you have the BoA shoulders and chest, the teams after that can for the most part skip all collection quests in Northrend and so makes things go a lot faster.
I initially also used the PvP BoA shoulders on my second group but switched a few levels into 70 due to the better stats on the PvE shoulders, particularly if you want to run some dungeons on the way to 80.
One last point on the shards from dungeons. Something they are worth keeping for is the gladiator PvP cloaks, they have a ton of spell power, stamina etc and will give your GS a nice boost without losing much in stats (the only decent cloaks IMHO are the Frost badge ones if you already have the crafted ones). Also if you use a druid for tanking at some point, the PvP gear also has a ton of stamina which is very useful.
All just my 2 cents