Our main water line is broken, we have hooked up a garden hose from a water source to our outside hose bibb, but we have no water inside. We understood this was a temporary fix, are we doing something wrong? The hose bibb is not a frost-freeze, and we have water coming out of the garden hose when it is not connected to the house.

So you have
1. closed the line that comes into the house from the water main. ** it has to be closed of course at the meter so the city water does not merely leak, but you also have to close it at the entrance to the home, or the water from the hose will just go out the leak also.

Also is there a back feed preventer on the outside water bibb, All of my outside bibbs have back feed preventer that will not allow water to come back though the house.

But if there is nothing to stop the back feed, if the inlet from the street at the house is closed, this should work, won't have a lot of pressure but should give you some water

I just want to confirm Chuck's answer: yes, it will work... Just make sure you close main water valve off in front of the house and the hose bib is part of interior house plumbing, not part of sprinkler system.

You do have the hose bib to which you connected the hose open don't you?

Odds are your exterior hose bibb has a backflow preventer, in many areas code requires these on outside hose bibbs to prevent contamanation if a siphon occors introducing outside water into the household plumbing. If you need to do this for temporary water, I suggest you run the hose into the house and connect it to your washing machine hookup.