necromancer

Hi i was wondering what stats and skills I should put into my necro..... it will mainly just be doing cows. Should I put a lot in mana and life? I know I should max out corpse explosion but I dont know what golem I should max out, I see a lot of necros use blood golems but dont fire golems do more damage? So far I know I should max out corpse explosion and some sort of golem, probably blood golem but what other skill should I max out or put a lot into like 3 skills? Anyone help would be greatly appreciated.