Re: Commiting a sin
If I remember correctly you were a warrior before, if you're interested in leveling another one, warriors are very powerful in PvP with a good group, and I know you already know how to tank and that's always useful. If you want to try something different, shaman and pallies are very strong PvP healers. If you want to go the FotM route, roll a warlock or hunter. Incredibly easy leveling and very strong in PvP either solo or with a group. DPS-wise, rogues are the best single-target DPSers currently and are very strong in PvP with a Hemo/Combat mace build (Mutilate is pretty decent still too). Mages are a ton of fun to play of course and offer fantastic damage as well as crowd control (which is in high demand for 70 heroic instances). Priests are versatile as either damage/support (shadow) or healers with a ton of utility (holy).
Profession-wise, mining and herbalism are the best money-making gathering professions (though it's a pain to have both at the same time, take mining+skinning or herbalism+skinning). Keep in mind your end-game profession goal when picking your gathering profession. If you want to pick a crafting profession early on, be aware that it will drain your cash flow which may make it difficult to get your mount at 40 (Alchemy is exempt from this). Enchanting is very expensive and should really be started much later in the game once you are able to farm instances for the greens you'll need to disenchant. Tailoring is very potent for casters near the end-game but you won't find a lot of use for the tailoring epic sets in PvP (for the most part).
Hope that helps. Really every class offers something great so it's hard to recommend a specific one. Do you have an idea what you want to do?
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