These are the bonuses applied when all pieces of an item set are worn.
This is not a comprehensive list, some things have been intentionally left off, some whole sets have been intentionally left off. As well, none of the actual items are listed, this is intentional as I do not want to give that much game information away so easily. Please refrain from 'helping' by posting that sort of information.
Each set is titled with the 'score name' of the set.
Armaboro Spirit
Affects : ARMOR by -70
Affects : HITROLL by 4
Affects : DAMROLL by 2
Affects : STR by 6
Affects : DEX by 6
Affects : CON by 3
Affects : RESIST_COLD by 25
Affects : RESIST_ELECTRICITY by 25
Affects : RESIST_HEAT by 25
Arcane Might
Affects : spell slots by +1 at level 7
Affects : MENTAL_ACUITY by 20
Affects : spell damage done by 10
Effects : IMMUNE_SILENCE MINDSHIELD
Chromatic Aegis
Affects : RESIST_ACID by 30
Affects : RESIST_COLD by 30
Affects : RESIST_ELECTRICITY by 30
Affects : RESIST_GAS by 30
Affects : RESIST_HEAT by 30
Affects : healing received by 30
Affects : HIT by 40
Affects : ARMOR by -30
Copper Blessing
Affects : ARMOR by -20
Affects : healing done by 30
Affects : RESIST_ACID by 20
Affects : spell slots by +3 at level 6
Effects : DETECT_EVIL DETECT_INVISIBLE DETECT_MAGIC IMMUNE_SILENCE
Power of the Deep
Affects : ARMOR by -70
Affects : regeneration by 75
Affects : damage taken by -10
Affects : healing received by 75
Affects : HIT by 30
Effects : NOCHARM IMMUNE_NEGATIVE_ENERGY
Cloak of the Black Dragon
Affects : ARMOR by -40
Affects : regeneration by 15
Affects : RESIST_ACID by 60
Affects : DAMROLL by 4
Affects : HITROLL by 4
Affects : STR by 2
Desert Rat
Affects : ARMOR by -20
Affects : regeneration by 5
Affects : MOVE by 20
Affects : HIT by 10
Erudite Sage
Affects : spell slots by +1 for all spell levels
Affects : LEARN by 20
Affects : HIT by 10
Brass Dragon's Heart
Affects : ARMOR by -60
Affects : spell slots by +1 for all spell levels
Affects : HITROLL by 4
Affects : DAMROLL by 2
Affects : damage taken by -10
Effects : CAN_FLY NOCHARM
Nature's Ward
Affects : ARMOR by -50
Affects : STR by 2
Affects : DEX by 2
Affects : HITROLL by 4
Affects : DAMROLL by 2
Effects : DETECT_INVISIBLE CAN_FLY SNEAK HIDE
Mishakal's Blessing
Affects : healing done by 15
Affects : spell slots by 16
Affects : WIS by 2
Affects : INT by 2
Affects : CONCENTRATION by 5
Effects : IMMUNE_CURSE DETECT_HOLY
Blue General
Affects : ARMOR by -50
Affects : HITROLL by 6
Affects : DAMROLL by 4
Affects : score criticals by 1.5%
Affects : RESIST_ELECTRICITY by 50
Effects : PROTECT_GOOD IMMUNE_FEAR
Red Dragon's Agility
Affects : DEX by 3
Affects : RANGED_HITROLL by 6
Affects : RANGED_DAMROLL by 6
Affects : SKILL wildfire by 10
Affects : SKILL evade by 10
Affects : SAVING_BREATH by -3
Effects : SNEAK HIDE
Spirit of the Beast
Affects : ARMOR by -50
Affects : HIT by 30
Affects : DAMROLL by 3
Affects : HITROLL by 3
Affects : RESIST_HEAT by 40
Effects : DETECT_INVISIBLE IMMUNE_FEAR
Green Dragon's Soul
Affects : HIT by 20
Affects : HITROLL by 2
Affects : DAMROLL by 2
Affects : SKILL fence by 10
Affects : SKILL riposte by 10
Effects : SNEAK HIDE NIGHTVISION
Heat Treated
Affects : DAMROLL by 3
Affects : STR by 2
Affects : CON by 2
Affects : damage done by 5%
Effects : CAN_FLY IMMUNE_HEAT
Kiri-Jolith's Retribution
Affects : ARMOR by -20
Affects : HIT by 15
Affects : healing received by 10
Affects : regeneration by 15
Affects : spell slots by +1 for all spell levels
Affects : skill rally by +10
Effects : DETECT_EVIL DETECT_INVISIBLE NOCHARM IMMUNE_CURSE IMPUNITY
Morgion's Revenge
Affects : ARMOR by -20
Affects : HITROLL by 3
Affects : regeneration by 25
Affects : score criticals by 2%
Affects : skill gaze by +10
Effects : DETECT_GOOD DETECT_INVISIBLE NOCHARM IMMUNE_DISEASE IMPUNITY
Cloud Giant Strength
Affects : STR by 2
Affects : CON by 2
Affects : HITROLL by 1
Affects : DAMROLL by 1
Effects : DETECT_INVISIBLE NIGHTVISION
Keeper of the Peace
Affects : STR by 2
Affects : DEX by 2
Affects : HIT by 10
Affects : HITROLL by 2
Arcane Magi
Affects : casting level by 6
Affects : LEARN by 5
Affects : HIT by 5
Affects : spell slots by +1 at level 5
Dark Dwarven Menace
Affects : ARMOR by -50
Affects : regeneration by 30
Affects : HITROLL by 4
Affects : score criticals by 1.5%
Affects : HIT by 15
Affects : RESIST_HEAT by 50
Effects : CAN_FLY NOCHARM NIGHTVISION IMMUNE_FEAR IMMUNE_BLEEDING