>>>I take no responsibility for you "bricking" your car for your not wiring things properly. <<<
Designing an EVSE, or charger as some say, is a great learning experience as well as having control of the form factor make it well worth the time and trouble to make one.
>>>READ THE ENTIRE INSTRUCTABLE BEFORE YOU TRY TO BUILD THIS!!!<<<
I also assume that you know how to work safely, and how to wire things in reference to a schematic.
Step 1: Tools and Supplies
J1772 EVSE control board - Open EVSE project (should be in Google Code, and they have great diagrams for EVSEs.)
J1772 Plug & Cord assembly - TucsonEV
Contactor/Relay/SSR - Electrical Supply
Box - Home Depot
12v PSU - Electronics Shop
Strain Relief for J1772 cable assembly - Electrical Supply
CR Magnetics 8420-1000-G - DigiKey
Heat-shrink tubing - Electronics Shop
Micro Torch/Heat Gun