In your case the values you need to look for when choosing an N-channel Mosfet are
VDSS: 120V +
ID: 10A +
Since you are going to be running these light for extended periods of times (Im assuming) then overshooting your expected voltage and amperage is a must, which is why i put +'s. so + 15-25, because it's not like more Voltage and amperage handling can hurt ya know?
Another thing you need to consider when running this kind of power through a mosfet is a heat sink.
Mosfets come with a metal tab on the back and there's a hole on the top of this tab so you can screw the mosfet to a heat sink.
when adding a heat sink to your mosfet you need to use thermal compound too. It's a thick pasty substance that comes in a syringe (Radio shack sells a couple brands of it), you apply this paste in between the heat sink and the metal tab then screw the mosfet and heat sink togethor. This thermal compound insures that the heat from the mosfet is properly transferred to your heat sink.
i know this sounds like a lot but it really is not that hard and if you decide on this, I would gladly walk you through it, if you'd like.
Also, I forgot to ask an important question. what "lights" did you want to use? (i.e) incandescent, led...ect, and how many?