Convince Me to play as a Mage

i have never played a mage character in any of the BG or IWD sagas. I usually play fighters or thieves or Fighter/thief. The mages I usually use in BGEE are Edwin, Neera, or Baeloth. But I alwys equip them with ranged weapons and the only spells I use are identify, and haste which I know isn't optimizing their abilities.
So Can someone give me a small tutorial/analysis on using a mage to their greatest potential.