EDM Information Wanted

Can anyone direct me to basic information on EDM techniques?

I'd like to cut 1-2 inch diameter 2-D freeform shapes out of
18-26 gauge silver. Interested to find out what kind of power
supply might be needed, what electrolyte is used, and whether
I could use an open loop vertical axis feed or will need to
build a closed loop system.

Thanks,

- Brad Smith
Los Angeles