Bukkit

Creating You first shop

Stand where ever you want and type the following command /trader create Admin Shop

Side Note: You can use colors for the name as well!
Example: /trader create &dAdmin &eShop!

You can also use any minecraft account name.
You will get their skin, instead of the default Steve one.

Add items to your shop!

You trader is put into 'Manager Mode' as soon as you create him.
You enable and disable manager mode by punching him.
Verification will be displayed in chat of his status.

Make sure your trader is in manager mode and right click him.
Up pops open the manager mode window.
There are 4 wool blocks on the bottom.
Unlock Stock, Limit Management, Price management, and Sell stock.

Click on Unlock Stock.

Now you are in the actual shops inventory. All you have to do, is drag the items you wish to sell (from ANY PLUGIN TO!!) from your inventory and place it into the traders inventory. Stacks are supported too.
Now, remember to left click the yellow wool (Lock Stock) to close the Stock window. Don't worry if you forget to click Lock stock. Just try to get into the habit. This will reduce any bugs you may get.

Add prices!

Once you click the Lock stock wool, it will take you back to the main menu. (the menu with the Unlock Stock, Limit Management, and so forth)
Click on the black wool. (Price Management)

You are now in the Price Management menu.

Using specially designated blocks, you can set the price for any item. Below is a table of items and their price settings.

Now, don't make this harder then it really isn't.
You simply left click ONCE on a price block and then click on the item you with to change the price on.
Left click raises the price, right click lowers the price.

Example:
I want to raise the price on a diamond sword to 500.
I add a cobblestone block to my inventory.
I punch the npc I want to edit. I right click him to open the management window.
I click on Price Management.
I left click cobblestone ONCE!
Then I left click the diamond sword 5 times.
Then I place the cobble back into my inventory.
If I am done setting prices, I ALWAYS click the red wool (back button). You may lose all your price settings. You may not. Why take the risk?

Selling items TO the trader

It's the exact same way to setup a buy shop.
When you punch the trader to put him into manager mode,
right click him, the click on Sell stock.

Patterns

Each pattern starts with it's name as the main node, and a type that needs to be set to price like below:
pattern_name:
type: price

After that is done you can setup the following three nodes for that pattern: all, sell, buy
The all node sets prices for both stocks, where the sell nodes sets prices for the sell stock and the buy node for the buy stock.


In each you can set the following nodes: all, sell, buy, tier_name

I will first show you a sample pattern and then continues with explaining :D

example

pattern_name:
type: price
all:
- 35 p:12.00
- 35:3 p:12.12
- 3 p:4
- sand p:55.5
buy:
- 0 need to unlock the stock first.
After its unlocked only 1 UI woll will show up. Now you can add any item you want to the stock, right clicking, left clicking, shift clicking, anything clicking you want. changes are saved only after clicking the "lonely" UI button.

Items will preserve their settings if no changes are made to them (excluding their moving).
So you can move an old item to a new slot, but you cant change it's amount. Amount can be changed by shif clicking an item in stock mode.