1st: Mirrors pendant gives 25% more exp. Reach it as fast as possible (level 6))
Most important: grab the following things as soon as possible, cause you will earn more hp and energy each level:
Items raising Vitality:
Huntsman cloak +1 (obtained two times rel. early in game, level 3 and 5)
That's all, so maybe you want to level earth magic, cause it gives Vitality from time to time. It's not the best school of magic, but perhaps you can level two of them.
Items raising Willpower (you can wear two orbs or an orb and a shaman staff)!:
Zhanduls orb +5 (obtained on level 9, secret 4, referring on gamebanshee)
Orb of radiance +2 (obtained on level 6, gives continous light, spellcraft 5 needed)
Shaman staff +2 (also boosts the damage of earth magic, obtained in level 7, spellcraft 7 needed)
Conjurers hat +2 (obtained on level 5)
For later the items that raise the other stats:
Raising strength:
Pit fighter gauntlets +2 (obtained on level 9, secret 2)
Shield of Valor +2 (level 6)
Circlet of war +3 (obtained on level 9 on the ground, ice lizard area)
Bracer of fortitude +1 (Level 5 - Found in secret alcove while traversing western pit room.
• Level 7 - Found in alcove within pit chamber. )
Raising dexterity:
Pointy shoes +1 (obtained on level 2)
Flairfeather cap +2 (obtained two times, level 4 and in the treasury level 9)
Raising resistances:
Fire
Shield of Valor +20
Shield of the elements +15 (obtained on level 10, secret 3)
Tome of fire (usable item) +10 one time (level 6 in the treasury)
Fire torc (head) +50 (obtained on level 7)
Earth
Shield of the elements +15 (obtained on level 10, secret 3)
Serpents bracer +50 (obtained two times, level 3 and ...)
Air
Shield of the elements +15 (obtained on level 10, secret 3)
Cold
Shield of the elements +15 (obtained on level 10, secret 3)
Nomad mittens +5 (level 3)
Nomad boots +5 (obt. on level 2)
Frostbite necklace +50 (obtained on level 6)
Advice:
Reach level 6 as fast as possible and grab the Mirror pendant, the orb of radiance, the huntsman cloak(s) and the shaman staff.
Level up a bit and then go from time to time deeper, to reach Zhanduls Orb for +5 willpower.
Should be complete now.