To make money in the early levels:
1) Do the Collector's quest (the statures you find in certain ayleid ruins)
2) Order of Virtuous Blood quest: this gets you 250 gold for every vampire you kill.
(but DON"T kill Roland!!)
3) Join guild houses and take their valuables. I pick up most of the glassware as I do the mage recommendation quests and sell it to the guild alchemist. The Chorrol fighters' guild basemant has a smith who will buy the weapons lying around. Some of the books are quite valuable, too. (I hardly ever sell books though, personal quirk, I guess).
4) Arena fights: you get decent cash for this if you don't have to buy potions to win the fights.
5) Never pay for weapon recharging - it's a huge money sink - learn to do this yourself!
6) If Alchemy isn't a major skill you can earn quite a lot of money by making and selling potions. It'll make you look smart, too!
7) As mentioned above, once past level 5 or 6 dungeon diving starts to be much more profitable. Even before then Ayleid ruins with Welkynd and Varla stones can net you a very tidy sum. (I never sell these either even though I use them about once in a blue moon.)
Mara