lowe, you will just make loot tables with the chances for drops and such. Then add the tables to the creeps. Be creative and make some low level items too. If you dont know how look up the tutorial. For Elwynn you will need New Jass Gen Pack in order to save and its a big map so your pc needs to be kinda fast.
Item ideas:
Low level armor (lvl 1 - 5) (head,shoulders,chest,back,hands,pants,feet)
Look in the one mine map, i already made some items there. Copy down the stats and then add them to the other maps. That way my system will work right.
Boss items for the Kobold General in the Medium mine.(lvl 5-9)