How do I trade to someone

it depends on what you're trying to trade

Pet
> go to pet's page
> hit 'manage pet' button
> set the sale price as '1' (if it is set as '0' it will not register as being for sale) and 'Sell to User ID' box as the ID number of the player you are trading the pet to
(Krin intends to get a proper pet trading page set up at some point this year)

Item/equipment
> go to inventory
> locate item you want to send to the other player and select it
> hit the little envelope-with-arrow icon that is located under the inventory to open a popup
> Input the username of the intended recipient (or select contact) and input the CoD fee (0 if it's being traded for another item or just for free, or whatever the agreed price was) and hit 'send item'

Gold
if you need to send or recieve gold from a player, the recipient player takes a low-value item (usually a fairy mushroom) and repeats the steps for item/equipment trading, setting the price as the amount of gold. The person giving the gold accepts the CoD fee for the item, which takes their gold and transfers it over.
The sent item may or may not be returned, that's something to work out at the time if desired

Diamond/gold exchange
If someone is paying you diamonds for something, you use Currency Exchange.
Player to receive the diamonds sets up a trade that is "I pay you 1 gold for x amount of diamonds"
(> currency exchange
> swap the left dropdown so it's "Sell currency: Gold"
> leave the gold amount as 1, alter the "for:" amount to the agreed upon amount to be transferred)
> once the trade is set up, the other person completes the transaction, buying the 1g from their trade partner to hand over the diamonds.
(since obviously nobody but people doing these trades is going to trade their diamonds for 1 gold- just double check the player names and amounts to make sure everything is correct)