How do you make Dynamic Lighting work?

I have gone in and placed lines to block line of sight and light, but my characters with darkvision still can not see anything. How do I make it so they can see once their token is on the map. I am also having trouble figuring out lighting in DL, for example if I place a torch on the map, how do I let it emit light?

For Dynamic Lighting to work you need: 1) Enabled on the Map 2) Token has "Has Sight" checked 3) Something is providing light.  Either a token that represents a light source, the token with sight emits light, or more likely a combination of both.  For Darkvision, it's common to model it as having the token emit light in the Darkvision radius, say 60ft, then have the Dim start at something small (1,0, -5, etc), and have all players see light off.

Check out the wiki for full details, although as always Aaron has pretty much covered the key points... :)