Please do not sticky mods, it creates a mess and makes it difficult for new mods to enter the "market".
The Sovereign Modding Pack was released for E:wom and it is 100% usable and relevant for FE mods: https://forums.elementalgame.com/401142
Here are some threads that I have posted before that should be linked in a "master list" for tutorials/info:
General stuff:
[eINFO] Folder and Filename priority https://forums.elementalgame.com/417961
[eINFO] Getting FE ready for our mods - object sanity please https://forums.elementalgame.com/434780
Specific game mechanics:
[eINFO] About Stamps for random maps: https://forums.elementalgame.com/435333
[eINFO] Production Rules https://forums.elementalgame.com/419061
[eINFO] Soulbound items for heroes (from their moment of spawn: https://forums.elementalgame.com/426422
[eINFO] Modding Auto-defend: https://forums.elementalgame.com/427100
[eINFO] Modding the Maul mechanic: https://forums.elementalgame.com/417078
3d stuff:
[eTUT] Frozen models ripped from the game: https://forums.elementalgame.com/399409
[eINFO] Havok skeletons to max/maya: https://forums.elementalgame.com/434510
[eINFO] Havok animations export to 3ds max: https://forums.elementalgame.com/434909
UI:
[eINFO] Some introductory information to modding the UI: https://forums.elementalgame.com/434988