The ways of power.

Skill at arms:  weapons, tactics, leadership
 Highest: gladiators, knights, silver daggers, followers of war-gods
 Medium: armies and mercenary bands
 Lowest: children of nobles, bandits and brigands

Craft of nature: foraging, herbalism, mineralism, healing, etc.
 Brotherhood of far-rangers
 Barbarian tribes, nomads, other non-city folks
 Healer's Guild
 Alchemist's Guild
 Followers of nature-gods or spirits

Barehand combat:
 Artmasters
 The secret brotherhoods: White Fire, Grey Hand, New Moon.
 Wandering masters, pacifist priests, etc.
 Temple and palace guards, for places where weapons aren't allowed.
 
Shadow ways:
 Thieves and assassins guilds
 Royal spies and spy networks
 The secret brotherhoods
 Followers of night-gods
 
Psionics:
 The full powers and training are taught only on the island of Avalon,
but imperfect subsets of it can be learned from odd sects and cults.

Spiritualism:
  Necromancy, clericism, druid-magic.
  Churches, wandering priests, etc. are all around; revelations also
happen occassionally.

Magecraft:
 One or two spheres -- apprenticed to a random mage.
 Multiple spheres -- Academy training, odd heritage, or multiple
masters(rare).