This'll take you 5 minutes, 10 tops:
(1) Pick up one of these at your equivalent local store:
Certified 12V Additional Accessory Vehicle Power Outlet | Canadian Tire
(2) Remove passenger/rear seat (key)
(3) Remove the two bolts that are revealed by #2 that allow you to remove the main/driver seat.
(4) Gently pull the battery terminal covers off.
(5) Connect device in #1 and reverse order items 2 through 4 and you're done with electrical part.
As far as placement, you can pretty much zip tie the thing in where you want, but I tend to keep it in the back seat and then whenever it's needed, just pop the back seat off, pull the outlet out, hook it up to whatever, and then let it hang...
IF you're planning on adding lots of electrical goodies, a setup like this is handy:
http://www.canyonchasers.net/shop/generic/relay.php