I'm just starting out as a sweet, pretty Wood Elf named Jo. I plan to be the sneakiest little thing that ever hit Tamriel. I had a successful break-and-enter at The Red Diamond but now I'm not sure where to unload the stuff. I tried The Copious Whatsit, thinking he might accept it but he won't. So where do I head with the loot?

You have to sell the loot to fences. Only certain merchants will buy stolen goods, and almost all of them are part of the Thieves Guild and will not barter with you if you aren't part of the guild. There is, however, a merchant who will buy any stolen goods regardless of your factions. Manheim Maulhand, the owner of the Inn of Ill Omen, south of the Imperial City and north along the road from Bravil.

Sounds like your best bet is to join the Thieves Guild.

An alternative is the Thieves Den DLC.

Old Manheim only has 50 gold to barter with, so that is the most he will pay for any single item (assuming you don't have super high mercantile perks yet).

Joined the Thieves Guild and am off to Bruma to peddle my stuff to Ongar. Tempted to steal a horse but running will build up my Athletics.

Join the theives guild,then look for a guy called Ongar the world wearly in Bruma.he's the man....