Skills
A quick list, most of these are self explanatory I think. Two kinds of skills exist: percentile skills (e.g. climbing, jumping) and two level skills (a Basic and a Master level) but they are grouped into 4 groups:
1. martial skills
fistfighting, wrestling, weapon usage, shield usage, weapon throwing (not just darts, knives, shurikens can be thrown... but two-handed swords too!), breaking weapons, disarming, heavy armor usage, dual wielding, blind fighting, weapon knowledge, leadership
2. scientific skills
writing/reading, language, ancient-language, meteorology (weather predicting), cartography, heraldry, mythology, history, theology, architecture, poisoning/treatment, herbalism, healing (not magical but in the practical way, with surgery and stuff), Psi (psionic abilities, more later), alchemy, physiology (this has some connection with necromancy), magic use, demonology, runology, gem magic
3. lay skills
animal training, etiquette, tracking (prey for example)/removing tracks, bushcraft (kinda), hunting/fishing, horseback riding (or any other rideable animal), wagon/chariot driving(?), swimming, sex (leading to situations from awkward to funny and back in every color), sailing, singing/playing an instrument, dancing, onomatopoeia (wtf is this in english? sound/voice imitation?), appraising, trapping, tying knots, juggling, running, profession, climbing, falling, jumping
4. criminal skills
brawling, backstabbing, cardsharping, wiggling out of ropes, camouflage/disguise, sneaking, stealth, tightrope walking, pickpocketing, lockpicking, finding traps, finding secret doors
Phew. That's a lot, I need a rest.

Every class gets certain skills by default and some can be bought at character creation with Skill Points to supplement these also on leveling up. Fighters get lots of SPs surprisingly so it's a very versatile class. With a decent intelligence score it can diverge from the usual grunt route.
Only percentile skills can be tested, at two level skills it's fairly obvious if the character can do a certain task or not. Also in some cases the player can be asked to act the situation out. Great for singing if you don't mind a little blood from your ears.
Of course hardcore players changed the two level system into a five level one. This idea was also incorporated into later rulebooks.

I dunno what picture to post with this so you get another map. A poster, it's fairly new and I think it has the CoA of all the states except the smaller city states. Looks good but for legal reasons this map probably isn't official.