Only a few of these quests are for Hillsbrad itself; Southshore is a centre for quests into Alterac as well.
Start off at about 30 with these:
Lieutenant Farren Orinelle – Down the Coast
Chef Jessen – Soothing Turtle Bisque
The first quest is a series, starting with murlocs, then naga, and ending with a trip to Stormwind. Murlocs are to the west, naga to the east, and turtles along the stream. If you get a chance, follow the stream all the way north into Alterac and Chillwind Point, then pick up the flight path in Eastern Plaguelands. The highest mob you are likely to meet is a 34 hulking mountain lion. You can find soothing spices in the NW building, with Bartolo outside. Mobs for these are all around level 30.
Warlocks will also want: Krom Stoutarm, Ironforge – Tome of the Cabal. The is in one of the further murloc camps, west of Southshore, the one where you first see different named mobs. The clickable is on the ground at the water’s edge, and is hard to see from the land.
After this, you should probably take Phin Odelic – Hints of a New Plague?, and go to Arathi for Captain Nials – Northfold Manor and the first troll quest.
Come back in a couple of levels, 34-36 or higher. In the town hall, start with: Magistrate Henry Maleb – Syndicate Assassins. You need to go to the open area in Alterac, just north of Tarren Mill. Mobs here are level 32-35. On the table in the middle of the camp is a scroll with two further quests. When you return to Southshore, one of these will send you to Ironforge. You might as well do this straight away.
When you get back, the continuation quests will send you into Strahnbrad, in Alterac. Take three more quests to do there on the way: Darren Malvew – Costly Menace, kill animals in Alterac just south of the yetis; Bartolo Ginsetti – Bartolo’s Yeti Fur Cloak, and Marshal Redpath – Crushridge Bounty. You will need a Hillsman’s Cloak, made by leatherworking, to complete these. In theory you can get the furs from the yetis in the cave in Hillsbrad north of Southshore, but I have never seen them drop here. Once you have the yeti furs, move on to the ogres, and then to the Syndicate in Strahnbrad; just follow the road to the north east. This will leave you with the head of Nagaz to collect. Nagaz is level 40, guarded by level 38-39s. He is in the house on the shore, some way outside Strahnbrad to the north west. Click the chest close to Nagaz to get another quest, and another trip to Ironforge.
An option to consider before taking on Nagaz might be to switch back to Arathi for Wand Over Fist, then return to Arathi for Faldir’s Cove.
If you are lucky enough to be in Southshore when the Syndicate Assassins arrive, manage to kill one and it drops a contract: Shadowy Assassin – Assassin’s Contract. Assassins are level 37/38. The follow on involves killing Baron ??, who can spawn in the basement of the large building in Strahnbrad, or in any of the camps to the north west (on the way to Nagaz).
Milton Sheaf, Stormwind – Southshore 38