Necromancer - What should I train?

[hodurkolgrim]

I'm assuming by hitting level 60 I'll run out of practice/training points. As a brand new (level 5 Gnome Necromancer) player, I've read that it can be helpful to train Sense Heading and I've already spent one point into Meditation. What else is necessary to train up? I understand Channeling, Alteration, Evocation, Conjuring, and Dodge + maybe a weapon skill, is there anything else that's considered absolutely essential? I don't want to waste them early on and somehow screw myself! I've checked the wiki pages and guides on necromancers but they're rather vague.

P.S.
What's the skill "specialization"?