After researching various kits online and in stores, I ended up choosing this kit by Lowe's store brand for lighting: Portfolio. It was a pretty cost effective kit-- $60 for 6 lights, including the transformer. I ended up using two 6-light kits and a one stand alone bollard for the one place where there wasn't anything to attach a light to. The photo above is the contents of one of the 6 light kits. 
The lights were pretty easy to install... just mark where you want them, level, and screw them into place.
The lights attach to the main power cable from the transformer. They pierce the cable with little prongs. Here you can see the wire guide, and I'm about to screw on the cap that will clamp the wire down onto the sharp prongs.
On the deck, I installed the lights onto posts, and ran the main cable under the deck. I secured everything with nail-in cable guides and zip ties. On the path, I installed the lights on the ends of the railroad ties that line the path, and buried the cable in the dirt alongside the railroad ties.
The transformer has a photo-sensitive cell, so the lights come on when it gets dark and turn off when it gets light. They can also be set to turn off 4, 6, or 8 hours after dark.
