You can find my curated list of add-ons for World of Warcraft Vanilla (game client 1.12) here, and World of Warcraft: Wrath of the Lich King (game client 3.3.5a) here. Some add-ons are are considered essential to anybody who is raiding with a guild.
I will be adding extra information, help, screenshots and videos to each of these add-on pages as I find the time to do so.
Please feel free to contact me directly via [email protected], or in-game on Dalaran-WoW with any requests or suggestions.