accessory outlet in the arm rest console.

 

I would like to charge my mobile phone in the car, even with the key out of the inginition.

 

A timer circuit to shut off after a couple hours would even be better!

 

No idea where to start. I know how to solder wires, but everything after that I would be making up on my own.

 

Any help would be appreciated.

Got a local Radio Shack? They should have everything you need with the possible exception of a socket.

If I were going to do this I'd skip the socket and just take a charging adapter and cut off the socket end. Then I'd extend the cord to the power pick up for the lighter. I would put an inline fuse in the hot side. It would be an easy job.