Indulgent Bakery

the only person you can hire is aclerk to attend the till but you don;t really need aclerk as the other sims wil just buy the items and the money goes into your household funds IF your sims own the bakery , your sim/s are the ones who do the bakein and stock the shelves and chill display

your sim needs to bake the goodies either at home if at home wait for the sim to put the goodies down after baking them then place in the personal inventory use the map view to find the venue then zoom in with the camera then drag and drop the goodies from the inventory   or bake in the venue one at a time wait for the sim to put the plate of goodies down after baking them at the venue then you go to buy mode drag and drop the plate of goodies to the display case

if your sim owns the venue then you can use a cheat if you don't want to keep baking if your sim owns the bakery then click on the wall option- real estate-option-buy on this lot then  hold ctrl+shift   click on the oven debug serve say cookies select the variety of cookie you want say sugar cookies then a plate of the cookies spawn in the floor then grab the plate and place in the display fridge  

if the bakery is un owned in the game food will not auto spawn, it cuts out the completion if your sim is the only who owns the bakery all profits go to your household

the lot type is hangout so once the business hours of the day are over( if you had set business hours) sims will still hang around and will help themselves to food in the fridge as hangout's are open 24/7 one way to is bake the goods at the home place them in the inventory go to the lot and drag you don't actually have to send the sim to the bakery just use the mouse to pan the camera over to the bakery and then drag and drop the goodies to the display case  here is link to thread with tips on how to run the bakery it seems hard at first but in no time at all you'll figure it all out

if you don't own the bakery in whatever world you play in when the goodies are gone they are gone

http://forum.thesims3.com/jforum/posts/list/748010.page

edit to add

your sims can bake the goodies at home for themselves too place the baker oven on your lot once the sim bakes something  they'll place the baked item on a counter you  drag and drop the goodies to the fridge and they can then eat the goodie as leftovers if borthday cahe or wedding drag and drop to sell from the sims inventory