I'll list a few topics that I think will keep coming back with sources that might help:
What quests are there for each dungeon?
Wowhead is probably the best resourced WoW fan site and it shows. Articles show a completeness and a professionalism that isn't always there on some of the other fan sites.
The inidivual dungeon guides are in both written and video format making them great to plan efficient runs. Quests have their pre-reqs explained so you can prepare those before starting.
This one is still in its early stages when a lot of the links are incomplete. I imagine it will fill up pretty fast. (You can always register, dear reader, and help them out). Where there is data it's very good and it's Classic specific which matters.
Not Classic specific but most data hasn't changed much. Also a good place to look up quests.
What's Best In Slot?
Pre raid gear comes from:
Head: Blacksmith item or Blackrock Depths. Enchant with Libram which need Black Diamonds from BRD.
Neck: BRD. Also Onyxia attunement quest for fire res.
Shoulders: UBRS. Exalted with Argent Dawn for the enchant.
Back: Stratholme. Also UBRS for fire res.
Chest: BRD. Mail item so Hunters and Shamans will expect priority.
Wrists: BRS. BRD for fire res bracers.
Hands: Scholomance. (Note Edgemaster's Handguards best for threat. BoE world drop).
Legs: UBRS/World Drop. Enchant with Libram which need Black Diamonds from BRD.
Boots: Scholomance. Mail item so Hunters and Shamans will expect priority. Also boots in Stratholme for Fire Resistance.
Ring: Maraudon and Scholomance. Also BRS quest/world drop for Fire res.
Trinket: Maraudon and BRD.
Main hand: Scholomance.
Shield: UBRS. Enchant with Blacksmith item Thorium Shield Spike.
Ranged: LBRS. Ranged item so Hunters will expect priority.
Enchants from the Enchanter profession will be covered in a separate blog post.
This list is pretty interesting for our late levelling. Pre-raid end game and even the first few weeks of raiding are about completing this list so that we can be at our optimum. And some of these dungeons start well before level 60.
Also note that many of these picks are controversial and the list may be subject to change.
How do I power level my professions?
Warrior class quests
Level 10: Defensive Stance.
Level 20-30: Brutal Armour
Level 30+: Berserker Stance and Whirlwind weapons.