Totally jgalt's review. Just some adds.
- pay close attention to the double and triple damage weapons
- pay close attention to the racial items (weapons, rings and boots)
- you do not really need a cleric to clear the Halls or outside. So you can try one of the computer characters.
- not mentioning that those characters usually have better stat points than anything you can create
- easy mode: use magic all the time and rest a log
- or you can try to win some battles with what you have at that moment
- if you want to multi-class a half-orc barbarian or warrior dwarf wait until you have two strikes per turn
- avoid too low wisdom characters (or try to protect them through magic).
- you do not really need a high dext sorceress (try anything between 10 and 12) just because you will find out a very nice armor soon (or almost soon in the game) but try at least a 8 in str
- easy mode 2: try at least one fast fighter/rogue character (more than 50) giving you an advantage against magic-based enemies
- buy anything you want (money is not a problem here)
- always, always in any D&D game, keep a concussion weapon (hammer, club, staff…) with you or be prepared to have the most bothering fights against any mediocre skeleton.