Mainly interested in finding out software for G4 that I was given so any help, especially not hugely expensive, as not 100% sure on G4's hardware condition yet, greatly needed.
Well, that's the problem in a nutshell -- you need contemporaneous applications to use the machine, and there's really nothing around other than some vintage-app collection sites. Here's the one resource for this that I trust:
http://www.oldapps.com/mac/
However, this site (great as it is) can introduce a new problem -- you want versions that aren't too new, but you also don't want versions that are TOO old for the OS version you end up running. Tricky, but if you're going to find a copy of a given app that can run on that system, that's the best place I know to do that.
One "old app" that can definitely help, however is TenFourFox (if you end up running OS X 10.4 or later) ... it's an unofficial version of present-day Firefox modified to work on really old systems. That will at least get you a workable browser, though there will still be some web issues (Flash, for example, is just flat-out not supported for that far back).