Below is a list of the various achievements available in World of Warcraft, together with links to pages explaining how to "achieve" them. If you spot anything that needs amending or updating, pleased let me know.
Tripping the Rifts (no longer available).
Love is in the Air (Valentines)
Peacebloom Vs Ghouls - not exactly an achievement as such, but it can be complicated to do, so here is the guide!
Deepholme Dailies - Fungal Frenzy
Pandaria "Rare" Hunting - Could We Find More Like That?