At a basic set up, For Skinning/leath go druid/hunter, for herbal/alch go rogue/priest, for tailor/enchant, go mage/warlock for engineer/weapon smithing/armor smithing (all of wich require mining) go pally/warrior, of course all classes can do as good at any, these classes just have advantages and compensations that align well with these professions.
as for best class by race straight up Troll Shaman and Human pally, the reason is for their racial traits, as for the imp being weak on your warlock... I have an imp, voidwalker, and sucubus... My imp still sees the most action... the thing to remember is the imp is NOT a pet, he doesn't tank, he's a DPS, he requires defence and he WILL run out of mana if you take forever to kill something, but if you can't get over the pet "tanking" thing then stick with your lock to 10 when you get a voidwalker he's not very strong but has alot of hitpoints and defense.
best class to play as a noob is hunter, it carries the benifit of a companion that doesn't get bored and leave group, the ability to tank AND dps (with the right pet) has feigndeath at higher levels for those sticky spots and you have range, melee, and the ability to both damage over time AND kill mobs that are running away without worrying about catching up... So why NOT go hunter ? well probly because so many noobs have ruined their reputation, one half of any servers "ninja" and "asshole" population can be traced to the hunter faction (because these are immature players they tend to stick to their biggest character, and that's normally their first one, and as we said, the best first character is hunter... end of mystery) So with a lack of sincere guild offers and a pissy time getting into groups for instancing, getting a hunter to 60 becomes a real choir, the first levels fly, but after 30 when everyone is hanging out in SM, you'll probly be hanging out in places they have never been, killing things they'll be to big to agro by the time they discover them... playing a hunter can still give you an edge though in learning the basics of combat and group interaction before trading up to a more focused class with a better rep, as a side note hunter will also give you a grewat edge in early PvP, until you hit the slow levels and classes start pinning your pet (Ice, entangle, sheep, sap, stun.. etc...) then wiping the floor with you.
So what should you trade up to ? (if you decide to) well, I'd simply type /join LookingForGroup then listen for who people are screaming for, Priest and warrior are popular as well as locks, the problem with warrior is no one really wants you in the group till you are big enough to damn near solo the instance, in wich case why do you need a group ? not much help leveling here though you will always find the smaller people grateful for your company. priest is nice enough, but you can't level for shit UNLESS you are grouped, wich works out ok except there are about three levels between each instance that you are not getting good exp from the smaller one and the players want you to be bigger for the larger one... that really blows as those three levels will take you as long to solo as the last 5 levels took doing group instances :-p wich brings us to 'lock, and the eternal arguement over wether a mage or rogue or lock has higher dps, the answer is 'lock, the imp and damage over time makes up for the smaller amount of hits as well as keeping agro far lower than a mage or rogue can while attacking, the 'lock also can soulstone the priest so that if the whole party dies the priest can auto rez and bring everyone else back to life, AND can summon people to remote instances, of course 'locks get more impressive as they get bigger so they always must argue with group leaders that get it stuck in their head the time they saw mages or rogues at level 5 one hitting mobs of the same size...
Not very helpful I know, but the classes are fairly balanced and it's a question of attitude and playstyle more than class abilities that determines wether you will be a 40 washout or 60 god -shrug-
LordDrakiss - Fountain of the obvious