To place a vendor, stand in a house that you are a friend of, where you want the vendor to be, and facing in the direction that you want the vendor to face, and dbl-click the Contract deed.
You can open up the vendors pack and place the items you wish to sell within it.
Some Commands:
- vendor collect - Collects the gold the vendor is holding for you
vendor dismiss - Dismiss you vendor. Be sure to collect the gold he is carrying first
The vendor charges per day based on the value of the goods he is carrying.
The calculation is as follows
- 20 gold for the first 1000 in value
0.05% of value of the goods in excess of 1000.
There are 12 UO Days in a Real World Day
This guide could be much more thorough, if anyone would like to rewrite or add to it I'd appreciate it.