Crafting recipes by gear will let you see at a glance all the shards that can be added to a given piece of equipment. Note that only one prefix and one suffix can be added to any one item.
Starting with the Menace of the Underdark expansion, new flexible slot shards have been added to the game. For details on flexible shards see the second post in this thread. For traditional crafting, see the following:
Main Hand Weapons
Armor
Shields / Off Hand Weapons
Docent
Clothing
Headgear
Goggles
Necklace
Cloaks
Bracers
Gloves
Belts
Boots
Rings
Trinkets / Rune Arms
Some effects have a parenthetical explanation of what they do, others don't. The main idea of these lists is to give you the keywords you need to search the shard machine.
There are a dizzying array of spell effects. To help get a handle on them, here are all the keywords associated with an energy type both for spells and weapons.
.............------------ Spell Power ------------...------- Weapon Effects -------....Energy
Energy Type..Passive.........Active......Lore........Standard...Burst.......Other......Absorption
-----------..--------------..----------..---------...---------..----------..-------....---------------
Acid.........Corrosion.......Erosion.....Acid........Acid.......Acid
Cold.........Glaciation......Freeze......Ice.........Frost......Icy.........Cold
Electricity..Magnetism.......Spark.......Lightning...Shock......Shocking...............Electrical
Fire.........Combustion......Inferno.....Fire........Flaming....Flaming.....Fire.......Fire
Sonic........Resonance.......Cacophony...Sonic.......Screaming..Thundering..Roaring
Force........Impulse.........Impact......Kinetic
Healing......Devotion........Ardor.......Healing
Repair.......Reconstruction..Mending.....Repair
Light........Radiance........Brilliance
Negative.....Nullification...Nihil.......Void..........................................Negative Energy
For easy reference, here's a list of the standard crafting slots for stat bonuses:
Strength: Belt, Gloves, Ring, Bracers
Dexterity: Boots, Gloves, Ring
Constitution: Belt, Necklace, Ring
Intelligence: Goggles, Headgear, Ring
Wisdom: Headgear, Necklace, Ring
Charisma: Cloak, Headgear, Ring
Quick tip: Persuasion, Good Luck and Charisma are the only ways to boost UMD apart from Command, which doesn't stack with persuasion and only goes on armor. A typical umd swap will be either charismatic (hat/ring) of persuasion, or if you normally equip charisma, underwater action (goggles/ring) of persuasion.