-Skills-
Skills represent some of the most basic and yet most fundamental abilities your character possesses. As your character advances in level, he can gain new skills and improve his existing skills dramatically. Each character has a set of 'class skills', determined by their class. It is easier for your character to become more proficient in these skills, as they represent part of his professional training and constant practice. You gain a +3 bonus on all class skills that you put ranks into. Each also has an ability score it's linked to. You receive a bonus to that skill depending on your ability score.
7: -2
8: -1
9: -1
10: +0
11: +0
12: +1
13: +1
14: +2
15: +2
16: +3
17: +3
18: +4
-Barbarian: Acrobatics (Dex), Climb (Str), Craft (Int), Handle Animal (Cha), Intimidate (Cha), Knowledge (nature) (Int), Perception (Wis), Ride (Dex), Survival (Wis), and Swim (Str).
-Bard: Acrobatics (Dex), Appraise (Int), Bluff (Cha), Climb (Str), Craft (Int), Diplomacy (Cha), Disguise (Cha), Escape Artist (Dex), Intimidate (Cha), Knowledge (all) (Int), Linguistics (Int), Perception (Wis), Perform (Cha), Profession (Wis), Sense Motive (Wis), Sleight of Hand (Dex), Spellcraft (Int), Stealth (Dex), and Use Magic Device (Cha).
-Cleric: Appraise (Int), Craft (Int), Diplomacy (Cha), Heal (Wis), Knowledge (arcana) (Int), Knowledge (history) (Int), Knowledge (nobility) (Int), Knowledge (planes) (Int), Knowledge (religion) (Int), Linguistics (Int), Profession (Wis), Sense Motive (Wis), and Spellcraft (Int).
-Druid: Climb (Str), Craft (Int), Fly (Dex), Handle Animal (Cha), Heal (Wis), Knowledge (geography) (Int), Knowledge (nature) (Int), Perception (Wis), Profession (Wis), Ride (Dex), Spellcraft (Int), Survival (Wis), and Swim (Str).
-Fighter: Climb (Str), Craft (Int), Handle Animal (Cha), Intimidate (Cha), Knowledge (dungeoneering) (Int), Knowledge (engineering) (Int), Profession (Wis), Ride (Dex), Survival (Wis), and Swim (Str).
-Monk: Acrobatics (Dex), Climb (Str), Craft (Int), Escape Artist (Dex), Intimidate (Cha), Knowledge (history) (Int), Knowledge (religion) (Int), Perception (Wis), Perform (Cha), Profession (Wis), Ride (Dex), Sense Motive (Wis), Stealth (Dex), and Swim (Str).
-Paladin: Craft (Int), Diplomacy (Cha), Handle Animal (Cha), Heal (Wis), Knowledge (nobility) (Int), Knowledge (religion) (Int), Profession (Wis), Ride (Dex), Sense Motive (Wis), and Spellcraft (Int).
-Ranger: Climb (Str), Craft (Int), Handle Animal (Cha), Heal (Wis), Intimidate (Cha), Knowledge (dungeoneering) (Int), Knowledge (geography) (Int), Knowledge (nature) (Int), Perception (Wis), Profession (Wis), Ride (Dex), Spellcraft (Int), Stealth (Dex), Survival (Wis), and Swim (Str).
-Rogue: Acrobatics (Dex), Appraise (Int), Bluff (Cha), Climb (Str), Craft (Int), Diplomacy (Cha), Disable Device (Dex), Disguise (Cha), Escape Artist (Dex), Intimidate (Cha), Knowledge (dungeoneering) (Int), Knowledge (local) (Int), Linguistics (Int), Perception (Wis), Perform (Cha), Profession (Wis), Sense Motive (Wis), Sleight of Hand (Dex), Stealth (Dex), Swim (Str), and Use Magic Device (Cha).
-Sorcerer: Appraise (Int), Bluff (Cha), Craft (Int), Fly (Dex), Intimidate (Cha), Knowledge (arcana) (Int), Profession (Wis), Spellcraft (Int), and Use Magic Device (Cha).
-Wizard: Appraise (Int), Craft (Int), Fly (Dex), Knowledge (all) (Int), Linguistics (Int), Profession (Wis), and Spellcraft (Int).
In addition to having a unique set of skills, each class receives a different amount of points per level:
Barbarian | 4 + Int modifier
Bard | 6 + Int modifier
Cleric | 2 + Int modifier
Druid | 4 + Int modifier
Fighter | 2 + Int modifier
Monk | 4 + Int modifier
Oracle | 4 + Int modifier
Paladin | 2 + Int modifier
Ranger | 6 + Int modifier
Rogue | 8 + Int modifier
Sorcerer | 2 + Int modifier
Wizard | 2 + Int modifier
As you can see, most skills have nothing do to in combat, but might have more use elsewhere. Other skills can be used in combat with some imagination.
For an in-depth look on what each skill does, click on the appropriate skill on this page: http://www.d20pfsrd.com/skills