Skills are entered in a format of Skilltype_Skillname. Look through the skilldata stuff in Shared for the skill names. For example, if look through Cone skills, you find "EnemyCharm", so to add that to an item, you add Cone_EnemyCharm to the item in the skills section. Multiple skills (and talents and anything else) are separated with a semicolon: Cone_EnemyCharm;Target_Restoration.
Talents are a bit less documented, but you can find a lot of them in the requirements. Here they are for reference. (Not all of these talents still exist, some have weird names, but you should be able to figure them out):
requirement "Flanking","WarriorLore 5"
requirement "AttackOfOpportunity",""
requirement "ResistDead",""
requirement "Carry",""
requirement "ExtraStatPoints","Level 2"
requirement "ExtraSkillPoints","Level 2"
requirement "Durability",""
requirement "AnimalEmpathy",""
requirement "Escapist",""
requirement "StandYourGround",""
requirement "SurpriseAttack",""
requirement "LightStep",""
requirement "ResurrectToFullHealth",""
requirement "Scientist",""
requirement "Raistlin","!TALENT_LoneWolf"
requirement "MrKnowItAll",""
requirement "WhatARush",""
requirement "FaroutDude",""
requirement "Leech",""
requirement "ElementalAffinity",""
requirement "FiveStarRestaurant",""
requirement "Bully",""
requirement "ElementalRanger","RangerLore 1"
requirement "LightningRod","AirSpecialist 5"
requirement "Politician",""
requirement "WeatherProof","EarthSpecialist 5"
requirement "LoneWolf","!TALENT_Raistlin"
requirement "Zombie",""
requirement "Demon","FireSpecialist 1;!TALENT_IceKing"
requirement "IceKing","WaterSpecialist 1;!TALENT_Demon"
requirement "Courageous","!TALENT_Escapist"
requirement "GoldenMage",""
requirement "WalkItOff",""
requirement "FolkDancer","Sneaking 1"
requirement "SpillNoBlood","SingleHanded 1"
requirement "Stench",""
requirement "WarriorLoreNaturalArmor","WarriorLore 1"
requirement "WarriorLoreNaturalHealth","WarriorLore 1"
requirement "WarriorLoreNaturalResistance","WarriorLore 5"
requirement "WarriorLoreGrenadeRange",""
requirement "RangerLoreArrowRecover",""
requirement "RangerLoreEvasionBonus","RangerLore 4"
requirement "RangerLoreRangedAPBonus","RangerLore 5"
requirement "Sight","RangerLore 2"
requirement "NoAttackOfOpportunity","RangerLore 1"
requirement "RogueLoreDaggerAPBonus","RogueLore 1"
requirement "RogueLoreDaggerBackStab",""
requirement "RogueLoreMovementBonus","RogueLore 2"
requirement "RogueLoreHoldResistance","RogueLore 5"
requirement "RogueLoreGrenadePrecision","RogueLore 1"
requirement "ExtraWandCharge","Wand 1"
requirement "DualWieldingBlock","DualWielding 1"
requirement "BeastMaster","Summoning 2"
requirement "Executioner","WarriorLore 1;!TALENT_QuickStep"
requirement "QuickStep","RogueLore 1;!TALENT_Executioner"