You have to love general chat in Hellfire Peninsula. It's a constantly scrolling line of the same questions asked every five minutes. So for those of you who don't want to go through the exhaustive bother of visiting Thottbot, or actually read the quest, here you are: answers to top five "well, duh" questions.
"Where's the <insert profession here> trainer?"
There are several trainers in the Alliance fort of Honor Hold. If you play Horde, don't ride into this town looking for trainers. It could go very, very bad for you. The neutral and Horde trainers are in Thrallmar, Falcon Watch and Shattrath.
The tailor grandmaster is in the second story of the inn. The skinner is in the main room of the inn at the bottom of the stairs, and the jewelcrafter is across from her, right on the other side of the front door. The alchemist is in the tower behind the inn, and the enchanter is two floors above him. You can find the herbalism trainer in an alcove between the two.
The leatherworker is a drunken dwarf (what else?) hiding outside the inn between it and the tower. The blacksmith and mining trainers are in the foundry across the way. The engineering trainer is a gnome located to the right as you enter the keep.
"Where do I train my cooking? And my first aid? And my fishing?"
The cook is in the backroom of the inn, he sells a cookbook to skill up to 375, but it's a limited supply, so check back later if he doesn't have it. The closest fishing trainer is in Cenarion Expedition in Zangarmarsh. And, the first aid trainer is in the Temple of Telhamat.
Reagents and poisons are sold by Magus Zabraxis, and she's in the tower next to the alchemist.