FYI: If you’re returning to WoW after an extended absence prior to patch 5.0.1, it’s possible that you’ll have more than the maximum pet limit and/or more than 3 of a kind. However, this will be the only time that you’re allowed to surpass these limits. You will have to pare down your collection, eliminating your duplicates, in order to add new pets.

Other methods have been discussed. For example, mods could be crippled. DBM didn't exist back then, and the other boss that did that I don't remember the name of, didn't do as much back then as DBM does now. If our goal is to recreate the experience as it was, then obviously not having DBM would be a reasonable way to accomplish that. DBM simply existing, makes the game today easier than it was. So disallow it. Again, this is completely consistent with the spirit of vanilla. Remember one-button-decursing? That was nerfed. They crippled the capabilities of the modding API to disallow that because it made the game too easy. So what if they cripple it a little bit more to once again make the game less easy?

Step-by-step class guides are on the way!  The 1-12 Mulgore Guide is the first guide to get all the individual class steps.  At the top of the guide, simply select which class you are playing and the page will dynamically update all the steps in the guide for that class (both text and images).  The rest of the guides will be slowly updated overtime to include all the class steps, but you can see how it's going to work with the 1-12 Mulgore.  I want to thank crazyK and his Placeholderguild for helping me out with the individual class content.  They are allowing me to get the 1-60 Alliance guide done while also getting all the class steps done at the same time, so everything can be ready for Classic launch (hopefully).
Thanks so much for the replies. I think I am somewhat of a collector/roster builder. I go around doing the dailies but I also like buying pets just for their looks. I watched hazelnutty on youtube last night. I think I will focus on doing the expeditions when I have time to get all the pets that come from that. Then I will go back and do old raids like Eekwibble suggested.
Much like an encounter with a wild pet team, PVP Pet Battles are turn-based. However, unlike the PVE version, the PVP combat system is timed and any ability for each round must be chosen within that time limit otherwise it will assume you have passed a turn. A time penalty is applied if you take more than 15 seconds to choose an action, resulting in progressively shorter round timers for you.
I used Zygor for legion and BFA, used AA on an alt for BFA. Personally i like Zygors format more. I like being able to target things like achievements. I used Zygor to get my Mindworm and my Lucid Nightmare as well as finish the Rep grinds for the allied races. I have zero complaints. My experience was great. I also used Zygor for some professions, recipe acquisition, a couple mounts, all of the Suramar quest line. Thank God for that. And for the last zone of Draenor on my Demon Hunter.. i forget the name.. Whatever the big daily hub thing was called.