I have a fairly large transformer that has 6 wires to one side and 5 to the other. What kind of transformer is this and what are the different wires for? Which is the primary and sedcondary?

It could be a power supply transformer. I If you can pick out a pair of black wires, they may be the primaries. The other leads are to supply various voltages, at least one of which is center tapped for a full wave rectifier.

It could also be a light ballast with various primaries available.

Sorting things out without a diagram from the manfacturer could be tough.