Tol Barad isn't accessible until level 85. Of the two regions, Tol Barad and Tol Barad Peninsula, each offers unique opportunities with the Herbalism gathering profession.
The main drawback of Tol Barad is that you can't fly. This drawback, however, creates a situation where many farmers will shy away from the zone in favor of other Cataclysm zones where they are able to fly. Also, the herbalism and mining nodes in the zone are densely packed, so if there aren't other players farming here, it can be a good alternative to the over-farmed areas in other zones.
The diagram shows two areas that can be especially fruitful: The first is the canal running through Tol Barad Peninsula. This is a fantastic Azshara's veil route that can net 6-8 nodes per trip if nobody else is farming. If you have a swim speed potion or seal form, this is a great Azshara's veil farming spot, though you will need to find other things to do while waiting for the nodes to repopulate. Also, beware of Tank at the top of the Azshara's veil path. He is an elite Shark that occupies the water where you'll be swimming.
The second decent spot in these two zones is in the PvP area of Tol Barad. There are many Whiptail nodes in a small location indicated on the map. While only 3 or 4 nodes will be up at any given time, if there aren't other players farming in Tol Barad, it can be an easy half-stack for a minute run-through while you are running a route around the zone looking for other things. The crocolisks that inhabit this area have a small aggro range and are very slow when running, so you typically don't need to fight them.
Beside Azshara's Veil and Whiptail, Tol Barad has a lot of Cinderbloom in standard Cinderbloom-growing areas, which are fairly evenly distributed throughout the zones. If you happen to be a Miner and an Herbalist, the Tol Barad Map can almost make up for not being able to fly. You just have to think of things as condensed, so while you may not be riding as fast as flying, you also don't need to go as far to get to the next node. Elementium, Rich Elementium, Pyrite, and Rich Pyrite Ore nodes are plentiful throughout each zone. A good farming option in the zone is to farm Embersilk cloth from the many groups of humanoids that inhabit the zone. This along with the daily quests makes Tol Barad Peninsula an excellent all around choice to pad your World of Warcraft gold coffers at level 85.