THink my Frost Mage is ok......Follow

Looks ok, couple of gear upgrades I would look for are Destroyer's Mantle which is from a group quest in Hellfire which starts with a drop off the elite Collosi (Collosusses?). Try and find a group for the Collosal Menace quest and hope the item that starts this chain drops and the group is happy to do that together.

Second is Vengeance of the Illidari which starts with an item that drops off a mob from a soloable chain of quests at Shatter Point (I think), you will need a group for this quest though.

Spec wise I'd take the points out of Frost Warding and put them in Ice Shards. At 70 I'd want Ice Shards, Empowered Frostbolts, Winter's Chill (3/5-5/5 depending on other mages) and Clearcasting maxed for raiding (losing points from either aoe improvements or shatter for this).

I'd have these as a bare minimum for raiding 10/0/43 and then just fill in frost depending on tastes (my current spec focused on raiding)

For instances (which you can get some really good gear upgrades in, not to mention the reputation which will come in handy later) try not to stress too much. Some groups are better than others, but you can learn something with any group. Do put aside a couple of hours for finding a group and then doing the instance though as it can take some time and there's nothing more annoying (for a group) than someone leaving 30 mins into the instance.

Some basic grouping tips (sorry if they are patronising, I don't know how much you know about grouping):
1. Have a macro for sheeping to focus the target you want to polymorph, there should be one possibly in the stickies here, but otherwise definately on the main wow forums or wowwiki.
2. Have a macro for your water elemental and when you get a trinket with an 'on use' section (like the one above) include that in your macro to add some oomph to your WE. Be aware of aoe damage while popping your elemental (e.g. Nazan in Ramparts does fire bombs on the group, make sure your elem doens't end up standing in one).
3. Put decurse on an actionbar and keep an eye out for curses on group members. I generally wouldn't interupt your current spell to cure someone, but once you've finished casting it can be very helpful to decurse someone when needed. This is particularly helpful for Omor in Ramparts as he does a curse that will do damage to anyone close to that party member. Ranged can spread out to avoid this, but if you decurse the melee/tank it will help your healer.
4. Get a threat meter and hope your tank has one too, then stay below the tank on threat (or at least don't do more than 130% of the tanks threat). If the tank doesn't have a threat meter but another dps does then stay below them, possibly a little unfair, but at least it won't be you pulling agro off the mob and wiping the group.
5. Salvation is usually the best dps increasing buff you can get from a paladin unless you are vastly undergeared for the instance.
6. The leader should mark a mob to be killed first, focus on that mob only for dps (and reapply your crowd control if needed) but don't be afraid to frost nova mobs that are running for the healer (just be careful of other classes crowd controls which may not be easy to reapply if broken).
7. Cooldowns - I tend not to use these on normal pulls, instead I save them incase things go a bit wrong. But there's no real reason not to use your cooldowns every time they are available (erm obviously not including ice block when you don't need to ice blcok). For bosses let your tank have some time to build up threat (and you some time to build up winter's chill) and then pop WE and Icy Veins, you can also Cold Snap after using your cooldowns to pop them again (gogo dps). Just remember to watch your threat.
8. Everyone loves free food and drink, so don't forget to offer that to your group and you can brew some up while waiting for for the group to fill up, or people to get there.
9. Loot rules can differ between groups, so follow what the leader says (if they say anything - does not include listening to blatantly stupid people), follow what the others in the group are doing, or if in doubt, ask.