To recap on some basics of Enchanting You can:
Enchant other players items (including soulbound) by using the trade interface.
Trade dusts, essences and shards with other Enchanters
Enchant weapons, gloves, boots, cloaks, and chest pieces.
Have one imbue {temporary augmentation from some other means} and one enchantment {permanent augmentation from Enchanting or some other means} on a single item.
Re-enchant the same item multiple times to increase your skill level.
Keep enchantments on items when you die as they are permanent
You can't:
Disenchant other players soulbound items
Sell dusts, essences or shards to vendors
Have more than one enchantment on a single item.
Sell items with Enchantments for more money at vendors.
Reverse a disenchantment
Remove an Enchantment, it needs to be replaced by another permanent augmentation.
Patch changes to Enchanting
Patch 1.9.0 (3 January 2006)
Epic items that are level 51 and above will now disenchant into a Nexus Crystal. Also items that normally disenchant into Large Brilliant Shards have a very small chance of disenchanting into a Nexus Crystal. New more powerful enchanting recipes that require these Crystals can be found in the new Ahn'Qiraj content.
Enchanters can now turn some of their dusts and shards into magical oils. These oils when applied to weapons add a temporary bonus to magical damage or mana regeneration that stacks with permanent enchantments. The lower levels of these recipes are found on normal enchanting vendors. The higher level versions are found on special vendors and are rewards for high Zandalar faction.
The Enchanting Trainer in Cenarion Hold in Silithus sells some of both new types of enchanting formulae.
Patch 1.8.0 (11 October 2005)
Enchanter-made wands are now Good (green) quality and have had their damage increased.
Patch 1.7.0 (13 September 2005)
Timbermaw Reputation Recipes are no longer sold in limited quantities with a restock time. If you have the reputation, you will always be able to buy the recipe.
Enchanting an item with an enchantment that will cause the item to become soulbound will now prompt the enchanter with a warning message before the enchantment is cast.
Patch 1.6.0 (12 July 2005)
Additional Enchanting Recipes added to Timbermaw at Honored Reputation.
Additional Enchanting Recipes added to Argent Dawn at Honored and Revered Reputation.
Lokhtos Darkbargainer in Blackrock Depths now has many additional recipes that can be learned at Honored, Revered and Exalted reputation.
Patch 1.2.0 – 17 December 2004
Enchant 2H Weapon with Intellect is now correctly giving +3 to Intellect.
Enchanter's Cowl minimum level to use set to 28 instead of 38, as was originally intended.
Patch 1.1.0 7 November 2004
Enchanting is now complete, you can perform enchantments that require up to 300 enchanting skill. Enchanting recipes generally require more reagents for 200–250 skill items
Living Essence and Essence of Undeath drops decreased.
Beta Patch 0.11.0 – 28 September 2004
All equipped items made from professions have had their stats tweaked to make them more desirable.
Beta Patch 0.10.0 – 19 September 2004
Enchanters can now enchant leather and thorium (needed for some high-end blacksmithing recipes and soon other high-end recipes in other professions).
Stats on the Smoking Heart of the Mountain changed.
Spears cannot be enchanted with 2H Weapon-only enchantments.
Fist Weapons can now be enchanted (bug fixed).
Old enchanting reagents removed from vendors (they should have been removed last push).
Beta Patch 0.9.0 – 15 August 2004
Enchanting is completely revised and has had recipes added up to 200 enchanting skill.
Enchanting now requires the disenchanting of magical items to get the required components.
There are around 100 enchanting recipes.
You can now enchant soulbound items through the player to player trade interface.
Beta Patch 0.8.0 – 7th July 2004
Heart of Fire are easier to find in this patch.