Your boost gauge will have a fitting of some sort for the vacuum line. If it does not, you will need to get a fitting so that you can run a vacuum line from the boost gauge to the engine bay.
If you pop your hood and look at your firewall, you will see lots of grommets. Try to find one that is in the footwell on the drivers side. When you do this, feed your vacuum line through the grommet. Inside the car, route the vacuum line through your dash to your boost gauge. I highly doubt you will have to pull apart your dash to so.
As for the lighting of the gauge there is a positive and a negative wire. The negative wire (Most likely will be black) will go to a ground of some sort. The positive (Most likely white) will need to be T'd into a 12v switched power (Some sort of power source that is only on when your headlights are on).
It's a fairly straight forward install.