Things marked with * are those that have not been implemented in any game in the series as far as I am aware.
I do not take credit for most of the ideas implemented here, this is just my attempt at organising it into a workable system.
Skill (What it governs)
Short blade (Daggers and shortswords)
Long Blade (Longswords and claymores)
Blunt (Maces, hammers, polehammers)
Axe (Axes, picks*, halberds)
Staff (spears, polearms and battlestaves*)
Hand to hand (Kicking*, punching, fist weapons)
Marksmen (Bows, throwing weapons)
Block (Blocks, parries*, reversals*)
Armorer (Fixing and creating weapons/armour*)
Athletics (Speed of running, rate at which fatigue decreases, sprinting*)
Acrobatics (Jumping, dodgeroll/moves)
Climbing* (All climbing actions*)
Sneak (Sneaking, sneak damage)
Security (Lockpicking, pickpocketing)
Charisma* (Speechcraft, mercantile)
Alchemy (Potions, food, explosives*)
Restoration (Restoration spells)
Conjuration (Conjuration spells)
Illusion (Illusion spells)
Mysticism (Mysticism spells)
Destruction (Destruction spells)
Enchanting (Enchanting items)
Crafter* (Fixing and creating clothing and non-metal items*)
Character type (What skills it covers)
Combat (Long blade, blunt, axe, staff, block, armorer, Crafter, athletics)
Stealth (Sneak, security, climbing, marksman, acrobatics, hand to hand, short blade, charisma)
Magic (Illusion, conjuration, destruction, alteration, mysticism, restration, alchemy, enchant)
I still haven't figured out how to organise them by attributes, so any help with that would be wonderful. I also would appreciate any criticisms and/or queries regarding this system and will hopefully be able to answer questions.