There are currently 19 trainable skills in Guilds of God. All skills level up by obtaining Experience.
There are a total of 10 combat skills:
Melee Focus - Determines your accuracy with melee weapons, and allows access to higher tiers melee weapons.
Melee Power - Determines your damage output when using melee weapons.
Melee Defense - Reduces damage received from enemies using melee.
Ranged Focus, Ranged Power, Ranged Defense, Magic Focus, Magic Power, and Magic Defense all share the same traits as those above for their corresponding class.
Hitpoints - A passive combat skill, which determines the maximum health your character has.
There are a total of 9 gathering and creation skills:
Woodcutting - Allows you to cut down trees for their logs. Higher levels grant access to higher tier trees, and faster chop rates.
Mining - Allows you to mine ores and clay.
Fishing - Allows you to gather raw fish.
Cooking - Allows you to cook raw fish.
Smithing - Allows you to process the ores you mine to create armor and weapons.
Crafting - Allows you to create magic armor, and urns for use in Alchemy.
Fletching - Allows you to create bows and arrows for use in Ranged combat.
Firemaking - Allows you to create fires to use for cooking.
Alchemy - Allows you to create spells for use in magic training, including teleports.
Construction - Allows you to build on the lands of Guilds of Gods.