You will need one character with Loremaster to 2 to identify everything in the game. You can get Loremaster from rings and amulets to get the remainder 3.
I highly recommend having one character with 7 Perception and/or Light Stepper, since most people don't like to pump Perception. This will save you a lot of headaches when finding hidden switches and traps.
If you are planning to get weapon abilities, do not get any from the start. Only pump Tenebrium (you get it mid to late game) as Tenebrium weapons are higher damage weapons. The Tenebrium skill is good for any weapons regardless of type (doesn't matter if it's bow, crossbow, 1 handed or 2 handed).
Don't get All Skilled Up or Bigger and Better unless you are planning to respec your character.
If you are getting Man-At-Arms, get Dust Devil.
If you are getting Scoundrel, get Walk in Shadows.
The skillbooks are really difficult/impossible to get later unless the RNG gods like you.
Beware of using up unique skillbooks like Barrage and Lightning Bolt if you are planning to respec.
