Today I'll be focusing on Cooking in Cataclysm. Currently the Cooking trainers will only teach you two recipes over 400 skill. These are Blackened Surprise and Darkbrew Lager. The lager will be gray to you at 450 skill and the Blackened Surprise will be yellow. Unfortunately this doesn't make Blackened Surprise a viable leveling recipe. The toughened flesh needed to make it seems to only drop from level 82-85 mobs. Even if you could handle killing them, the drop rate is terrible. I tried farming the wolves in Twilight Highlands and got maybe half a stack after 30 minutes or so. I would estimate the drop rate at 15-20%. I think it would be a huge time waster to use this recipe, especially since it can't help you skip any of the vendor recipes.
If you're serious about leveling Cooking, I would be prepared to fish up what you need. It's so much easier to get fish in quantity and without killing mobs. Even with the efficiency of fishing to collect materials, you cannot level Cooking quickly. All of the useful recipes are on the daily token vendor. There's no conversion from WotLK tokens either, you have to start over with the new tokens.
Currently it's possible to level to 525 with three recipes. Each recipe costs three tokens, so that's nine days of questing before you can get the recipes to reach the new skill cap. All recipes are BoP of course, so you can't collect tokens on multiple toons or anything like that. It would seem that powerleveling Cooking isn't an option in Cataclysm.
The vendor sells three tiers of recipes. Eleven are available at 450 skill, another three recipes at 475, then eleven more at 500 skill. There's also a few recipes available for novelty purposes, but nothing you'd want to level with. Bear in mind that each day you complete the daily quest, you will get a skill point as well as a daily token. So when you start to level Cooking, you'll already have 9+ skill points right off the bat.
For the first recipe you purchase, I'm recommending either a Lurker, Lavascale or Trout recipe. Two of these fish can be found in Mount Hyjal, although the Lurker has a higher catch rate. Lavascale can be caught in Uldum if you want to brave that. Ultimately I would choose whichever recipe uses the fish you've managed to collect, it really doesn't matter all that much. These recipes seem to turn yellow around 465 -- at least mine did. However, we can't get any new recipes until 475 so you have to keep making this one. It took me 17 fish to get from 458-475. Even though the recipe was yellow for the last ten skill points I still got a point each time. It can't hurt to plan for 20-25 though, fish aren't all that hard to catch.
Once you get to 475 you unlock three new recipes. Only one of these uses fish, the other two are made with dropped items. That's not to say that you can't farm those items while you're collecting tokens, but I wouldn't go that route. So I'm going to suggest picking up the Pickled Guppy recipe. Highland guppies can be easily fished along the river in Twilight Highlands, there are plenty of spots to loiter with no aggro. My tests with this recipe have it turning yellow at 490, so you can get a good 15 skill points from it before it starts to give you trouble. But as before, we have to keep going because new recipes don't unlock until 500 skill. I was able to get from 490-500 by making another 13 items, which is still respectable skill points. You might want to collect 30-40 fish (or drops) to get through this phase of Cooking.
At 500 skill there's another eleven recipes you can learn, basically upgrades to the earlier versions of buff foods. These recipes incorporate a wider variety of fish, so I'd go with either a Mudfish, Sagefish, Rockfish or Fathom Eel recipe. This can be up to personal preference and/or accessibility to your toon. It took me about 30 items to go from 500-525 and reach the new level cap in Cooking. I think stocking 40 fish to cover this range should be sufficient.
I wish I could share some handy trick for getting this done more quickly. Unfortunately after trolling through the Wowhead data, I'm just not seeing one. Every recipe you could possibly use outside of the token vendor turns gray by 465. I can't find any way to shave down those 9 days of daily quests needed. It would seem that Blizzard just doesn't want us power-leveling professions on the first day.
Right now there's one potential short-cut, which may be removed before Cataclysm launches. Currently the recipe for Lavascale Minestrone can be used to skill up all the way from 450 to 525. This is most likely a bug as it's the only recipe like this. It could be considered an exploit to use it to power level Cooking and get a Realm First achievement. If you want to take a chance on using it, you might get lucky and have it still work for you. In which case you'd be able to reach the level cap in three days instead of nine. You could also get unlucky and have Blizzard revoke any achievement you get by using this recipe. I make no promises that this is a good idea, only that it may be possible. If you choose to go this route and get in trouble, that's the risk you take by using a possible buggy recipe to get an achievement they might not want you to get in that manner. Alternately, they may not care if anyone exploits a bug that didn't get fixed in time.
Here's the suggested progression:
450-475: Striped Lurker or Lavascale Catfish recipe (20+ fish needed)
475-500: Pickled Guppy recipe (30+ fish needed)
500-525: Mudfish/Rockfish/Sagefish/Fathom Eel recipe (30-40 fish needed)