Go to
viewtopic.php?f=4&t=1850&start=0 Mow Guide - First Steps. Control+F and type [MCHLG].
I'll copy/paste it here for convenience.
B. Using Merchants (AKA Trading) [MCHT]
First, the main purpose of Merchants is to make gold. After building a trade post and recruiting a merchant, you must send the merchant off to trade. Do this by clicking the Trade Post, selecting the merchant you want to send, determining the amount of gold to load onto your merchant near the bottom of the trade post menu (don't forget to actually load the gold), and then pressing the "Leave" button. Select your destination and press the other "Leave" button.
Note: The higher the level, the farther the merchant can travel at one time. Example: At levels 1-9, a merchant can travel to one village at a time. They must stop at every village. At levels 10-19, a merchant can travel two villages at a time. Instead of hopping on one-village trips, you can effectively "skip" a village and proceed directly to the next, farther village.
See the Merchant Leveling Guide [MCHLG] to find out how to make a profit and level up merchants.
The best goods to buy are goods with a high price/weight ratio, such as Silk (18/1), Western Swords (18/1), Aromatic Essence (18/1), Water Buffalo (17/1), and the numerous 16.5/1 and 16/1 products.
C. Merchant Leveling Guide [MCHLG]
Author: Peach
Merchant Leveling
The more profit you make on a merchant the more experience you get for that merchant.
First step is to click on your Trade Post and add items and/or gold. Items you can receive from the collection point and defeating various world mobs and lairs. After you have added items and/or gold you should click the "Leave" button.
Once you leave you need to get to a Trade Center to be able to sell. You can buy at villages but not sell.
Some people say that shorter distances work better because it is faster while others say that it's more profit longer distances. A long route that I see most people using is Rome where you buy Western Swords then head to Babylon (Persia) and buy Water Buffalo followed with the last destination as Changan (China) to buy Silk and return to Rome. You can look for the route that suits you the best.