There are 9 Skills. The skills can be improved by Leveling, by Skill Books and by Skill Trainers. (Trainers and Skill Book Locations) But even If you use the skill books and the trainers you can't max out all skills with out being a Jack of All Trades. The final destiny of them is plus 3 to all skills so you can arrange your points and unbind them to where you can get maxed out at level 37.
Increased chance to successfully harvest Reagents.
Blacksmithing allows you to repair your arms and armor as they become worn or damaged, as well as forge entirely new equipment. It also increases the effectiveness of Repair Kits.
Detect Hidden enables you to find hidden treasure caches, deadly traps, enemy ambushes, and secret doors.
Increases the amount of gold found as you explore the world.
Dispelling grants you the ability to dispel protective magical Wards without suffering harm.
Decreased difficulty when dispelling magical Wards.
Lockpicking grants mastery over the picking of mechanical locks, enabling you to bypass even the tightest security.
Decreased difficulty when lockpicking.
With Mercantile, you master the art of selling for more and buying for less.
Improves Buy and Sell gold costs at Merchants.
Persuasion allows you to talk your way into and out of situations that would normally require a different solution.
Increase your chance to persuade others to your way of thinking. Decreases bribe costs to guards.
Increases the time it takes NPCs to notice you, as well as decreasing their effective detection range if they are unaware of you.