The wiring will depend on the gauge you have. It will have instructions on how to wire. For tapping to get the boost you can tap the Y coming out of the SC or one of the intake plenums. I used the Y, some have used the plenum. The plenum will only give you one side numbers, if that matters to you. Typically you need to drill and tap a hole for a 1/8-27 NPT fitting, screw in a 1/8 NPT (male) fitting that has a 1/8' or 3/16" hose barb on the other side. Then connect that to your gauge.....

If you cant afford to tools to do this right... hold off until you can. Or have the gauge installed by a shop.