I've been working on my grind and have been loosely documenting along the way. I'm up to 66 now, and it's going pretty well. This is what I've done so far...
58 - Enter outland through the portal, following the quest chain until you unlock the Helfire Fortifications, then STOP doing quests in hellfire peninsula. I think the pre-requisite quest is "Forward Base: Reaver's Fall", at least for Horde. From now on, do Hellfire Fortifications daily. Grind on shattered-hand mobs (5 thrallmar rep each) until friendly, then start running ramparts. Continue running ramparts and hellfire fortifications until Honored.
59 - Between ramparts runs, head to zangarmarsh and start grinding on Marsh Dredgers and Marsh Lurkers (15 sporregar rep each) in the cave in south-eastern zangarmarsh. Remember this cave, you'll spend a lot of time here.
60 - Pick a side in shattrath (aldor/scryers) if you choose, but don't do any quests that give rep yet. start watching the auction house for the appropriate turnin items. I chose aldor and I buy marks of kiljaden or marks of sargeris that I see for under 50s each. I buy fel armaments that I see around 10g each. You won't start doing any quests until you hit honored with your chosen side with only turnins. Turn in your plant parts in Cenarion Refuge, then go to the auction house and buy the rest that you need for turnins to get you to honored with Cenarion Expedition. Save uncatalogued species until honored, then turn them in. Do all quests that give Cenarion Expedition reputation available at 60. There are some are in Terokkar forest too. Then grind in the cave until 61.
61- Do all quests that give Cenarion Expedition reputation available at 61. Then grind in the cave until 62.
62 - Do all quests that give Cenarion Expedition reputation available at 62 (don't forget count ungula). You'll need to run slave pens and underbog at least once to complete "Lost in Action". Do all the available quests that give Sporregar rep, then grind rep in the cave if necessary until you are honored. Go buy your Petrified Lichen Guard and put the best shield spike on it you can afford. I recommend Felsteel shield spike. you can buy arakkoa feathers on the auction house and start with the turnins for lower city rep at this time if you so choose. By this time, you should be honored with Thrallmar, start doing all the quests in hellfire peninsula that give thrallmar rep, including the chain that gives you Mag'har rep (we'll start grinding that later).
63 - Continue thrallmar quests (you're still doing helfire fortifications daily, right?) and any remaining sporregar or cenarion quests, returning to the cave to grind to 64 if you run out of quests.
64 - Head to nagrand and start doing quests that give mag'har rep along with the few that give consortium rep. DO NOT GIVE THE MAG'HAR ANY BEADS. Mag'har rep is easy to get from killing ogres. Give ALL beads to the consortium.
65 - Do the (one?) consortium rep quest that you can get at 65, and continue doing mag'har quests. If you tire of quests, you can grind ogres for the beads as a diversion.
This is where I am now. Any suggestions or tips would be appreciated. I'll review my notes when I get home (I'm at work now) and update this if I made any errors.