Need cash? Then make it the easy way, steal it. Just don’t ask anyone where to sell the stolen items at or the location of the fence.
From a fine reddit post:
You can earn close to 1,000 gold every 10 - 15 mins. Break in and search everything. There will be specific items that you sell to fences and you can sell up to 50 items a day and most houses will have 5 or so White and Green items. Maybe a blue if there’s a lockbox.
White Items - Sell for 30g
Green - Sell for 100g
Blue - Sell for 250g
Purple - Sell for 750g
Good luck on becoming a Thief my friends!
Edit: Houses to search are located in almost all major cities. You can also look around Taverns and Inns as well.
A good website showing the locations of homes to break into.