In order to power the lights you will need to wire each light through a transformer that is plugged into an outdoor electrical outlet.  You will have to calculate the number of watts that the entire circuit carries to buy the correct size transformer.  Most transformers have timers that can be set so that your lights will automatically turn on when it gets dark.  The wiring works exactly the same as with low voltage landscape lights.  Tap splices can be used to securely hold connections within the circuit. 

I have heard of some builders running exposed cables on low decks through rubber hosing to prevent squirrels from biting through the wires.  Outdoor lighting can be hardwired allowing you to activate the lights by a switch inside your house, but this will involve hiring an electrician.