Setting up a local testing server for PS3

Scenario:
Small local network
Preferred server: Mac Mini Intel Leopard Mamp
Primary development platform: Mac G5 Tower Tiger Adobe CS4 with all the trimmings Mamp
Secondary development platform: Mac Pro Laptop Intel Leopard Adobe CS4 etc. Mamp

Question…
How do I place my local site files on the Mac Mini "server" or a network drive so that I can access the same "local" files from both my desktop or laptop.

And, how do i set the Mac Mini as the "testing server"?
Would all the access privileges be set at the Mini?

And is Mamp, NOT Pro, able to do this?

And I expect that privileges for the individual files could be a problem working from two locations so what do I need to do to overcome that?

I don't want to keep any site files on either development platform so there is no chance of disparate files in two locations.

I've poured through all the forums and only circled around related questions. Nothing gets to the heart of what I intend.

Mick