Vacume pressure question

[jones]

I measured the vacume pressure @ idle (about 975 rpm) and it read 15 is this ok?
If this is an ok reading can I assume most of my air leaks have been found?
What should a reading be at a higher rpm say 2k or 3k?
Am I going about about finding air leaks with a vacume guage correctly or am I reading a value that has nothing to do with hoses leaking or overall poor sealing? ( I suppose I could pull of a hose while vacume guage is attached and see.. doh!)
I am just trying to figure this whole thing out, I am pretty new to it. Thanks

[pbanders]

15" of vacuum is a good reading at idle, especially if the car is fully warmed up. It is not a total assurance that you have found all vacuum leaks, however, but is a decent indicator.