If you are going to put resist spells on your char start them with that, however mostly pvm doesn't really need resist spells... SS is pretty easy to train so i would probably just buy that. however Melee can be rather difficult or time consuming to train so you might want to consider starting with that.
Alchemy doesn't really give you any bonuses in regards to damage, so if i were you id save that for another char.. otherwise you run the risk of having too much on the template and then you can't do anything efficiently.
if by chance you are on Siege then a craft skill might be warrented, however i do not play Siege and am probably not the best person to advise in that regards

..
so if you are going the Mage/necro template.. I would say
necro
SS
Mage
Eval
Med
melee.. (wrs, swords, etc)
extra into focus tacts, healing... etc kinda up to you on what you want