Thanks for the comment, Astrelle.
The source of all the recipes used should be shown, but I'll add a single reference list.
The guide is intended for power-leveling, so is optimised to reduce travel time. Hence the Horde guide spends a lot of time visiting a few zones very close to the Undercity.
But I know that it is used at lower level, so try to find a method that is still useful. This has become much harder to write with patch 3.1, because the places fish can be caught still scale up with level, yet only level 10 is required to catch and cook (almost) everything.
Feralas certainly can be used as an alternative to the Western Plaguelands, but it isn't terribly suitable for those at low level. I guess mid-level Horde have a specific problem getting through the Bulwark. The Alliance guide gives the option of traveling up from Hillsbrad Foothills, which is safe at about level 20+, so I'll add that to the low-level suggestions.
Now the Eastern Plaguelands are a real problem at low level, but so is ever similar zone. For example, the only part of Feralas with the same fish is Jademir Lake, which is surrounded by level 60-ish elites. I think the best suggestion for low-level Horde is to swim up to the Bay of Storms in Azshara.
Any other thoughts from others that have tried using the leveling guides?