Need some advice for a new Mage

[Elder Rogue]

I have looked at so many threads on this site and EJ.com trying to find the simple answers that I'm looking for, but all I'm finding are complex guides for creating an end-game PvE raiding or level 85 PvP Mage. I just created a Mage to play with some friends and I plan to level him up to 85 (I also have a level 72 Rogue that was my main from when I played WoW with a friend back in the classic and BC days). My mage is currently level 17 and I've spec'd him as Frost, but I'm not sure if that's the best build for my play style. I primarily play solo while questing, but I'll occasionally play with a friend or two (especially to do the instances/dungeons while questing) and I would like to use the Dungeon Finder to do a random instance or two. I'm not into PvP, but I would like to (eventually) do the end-game raids.

My biggest question is what spec I should go with (is Frost ok or should I respec already)? I've read so many guides that say Fire is better for PvE, but a friend said that Frost is the popular choice. I'm doing fine with Frost (plenty of mana and relatively no issues defeating any mobs while questing), but I find it a little boring honestly. Maybe it's just because I haven't been in on any big fights yet?

[DynastyMonk]

Just spec whatever you want to play as, you don't need a complex strategy or lots of planning, just play whatever you find funnest :/

[Heilige]

Frost is the popular choice for leveling due to CC and survivability + a pet. However while leveling, it's personal choice. At 85, Fire is the optimal PVE spec while Frost is the optimal PvP spec.