Actually, the queen bee teaches Aura of Command, not Enchant Weapon.
Free skills, and spell books you can buy (spoilers)
The Locus Inn - Skill System (individual paths, and a skill table for each class showing all level requirements)
or from
RPG Vault - Divine Divinity Skills XI (links to other skill sets at bottom of page)
Way of the Warrior - Path of the Warrior Gods
Enchant Weapon (Passive)
Level 1: Allows you to apply 1 charm. Required Clvl: 1
Level 2: Allows you to apply 2 charms. Required Clvl: 7
Level 3: Allows you to apply 3 charms. Required Clvl: 13
Level 4: Allows you to apply 4 charms. Required Clvl: 19
Level 5: Allows you to apply 5 charms. Required Clvl: 25