VacuumDiagrams

If you are going to replace your vacuum hoses, please do them one at a time. If only one hose is removed at a time, it's that much harder to mess it up.

How to read a vacuum gauge

You can get diagrams for free online at many places, see: User/Service Manuals and Docs

Interesting AutoZone.com repairguide vacuum diagrams for a bunch of vehicles, not Astro/Safari specific. They appear to be very good digitizations of old Chilton manuals. If you know the part, you can easily find out how it needs to be connected: http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0900c1528004c3cb