If you decide to register, you begin as a citizen of Ur, with nothing but 100 coins, and your health. To start, the profitable thing to do is gather and sell apples, wheat, and reeds. Apples along with wheat can be sold to the cook, and reeds to the weaver.

After attaining enough capital, there are many vocations one can choose to occupy themselves with such as wood cutter, hunter or builder. The game is a work in progress so not all things mentioned are fully implemented. UrMud is very open ended; you can hunt, build, gather, or just chat, there are no definite titles to persue, you simply choose whatever activity suits you at the time, if you own the required tools of course.

You can try trading to begin with(ie. buying things from the merchant at the right times, and selling to the craftsmen) but that is an unreliable way to earn a living, it is one of those things where you occasionally see a really good opportunity, and need to seize it, not a steady source of income. For instance I recently saw the cost of hides go way down at the merchant, but up at the leather worker, I profited about 250 to 300 coins. It's those little opportunities that supplement a steady supply from gathering or hunting, bottom line, don't bet the farm on trading. Although I'm sure you will find even more lucrative opportunities than that. Make sure not to forget that you need money/resources to make money/resources in trading ;-).