Creating a Merchant

To create a Merchant, follow these steps:

Create a Container

(and name it)

This is easier if you make a copy of an existing container, then remove everything from it (so you don't have to set up the model and sounds). Any of the chests starting with "Merchant..." are good ones to copy.

Add any items you want the merchant to sell to the container.
To give the merchant gold you can add one of the VendorGold<> leveled items to the merchant container.

Create a Container

Add the Container to the game

It is a good idea to put this somewhere the player cannot get to it (for example, outside the building in an interior cell)

Add the Container

Create a Faction

(and name it)

On the Vender tab, do the following:

Check "Vendor"
Enter your daily start and end hours for the merchant
Select a location for the merchant to offer their goods (for example, the shop cell). You can select "Near Self" to make the merchant sell anywhere.
Enter a Radius if the merchant needs to be within a certain distance of a reference.
Select the container that you placed ingame as the Merchant Container.
Select the type of goods the merchant will buy and sell from the Buy/Sell List drop-down menu (eg, VendorItemsApothecary or VendorItemsFletcher. These types are simple FormList objects containing keywords. You can also create your own. If you select "Not Buy/Sell", the type will be negated, and the merchant will buy and sell only items not matching the type. This can be useful, for example, if you are creating a merchant that will buy almost anything - just use VendorItemsMisc and check Not Buy/Sell. This is the configuration used by the pawnbroker Belethor in Whiterun.

NOTE: Regardless of the contents of the container, the merchant will only sell items matching her configured type filter.