Have a look at the VSD-E from Granite Devices, it can drive BLDC motors. I don't know of any DIY drive schematics etc for brushless motors. As for connecting it to the drive, the motor should have three wires and the encoder at least 6 wires for A+, A-, B+, B-, 5V, GND. You need to find a datasheet on the particullar encoder to find out what's what. Or you could trace out the circuit and figure it out but that's not easy of you're not used to that kind of thing.