1) When using the PN, are you stuck with having to use the default Constructs, Elements, Sheets and Views folders or can you customize that?
I think this was supposed to change with 2008 but frankly I haven't looked into it because the stock PN file structure is now our company standard!
2) How does it fit in with YOUR project structure?
See above!
3) Any good, easy to read white papers or tutorials (rather the help file) on how to use/implement this? Links? PDFs? Anything?
Matt, I learned by having some time ( I know: a luxury ) and getting my hands dirty. We customize EVERYTHING around here so our entire system has been streamed lined to utilize PN to the fullest. Sorry I can't point you to a source, but if you have any specific questions I'll be glad to give it a shot and try to answer.
The Project Navigator is the single best tool Mr. AutoDesk and Co has come up with. It has cut production time, seriously limited mistakes and misinformation, made my job so easy it's making me look bad, just a good solid tool: I hope you dive in and use it!!