A step in the right direction

Hi,
(ps. Happy to help too with the dgc charity site - how, when and where I can, I'm not sure, but if I see something I can help with I'll put my hand up.)

Wondering if anyone would care to share their thoughts on this. I think I need to start organising a better way of managing my site and future sites. So I'm wondering what options I have, and what might be an ideal setup to take me to the next level (man, does that sound corny!)

Currently:
What I have is a site being hosted temporarily (thank you kind host!). With a bunch of files there, being the actual site, and then a duplicate bunch of files on my own computer, but which are not set up to be visited, they're just the files... unhinged. (I also have a home server set up, but it's currently not being used - I could fire it up, but I think I prefer the concrete nature of seeing the site work in a 'real world' environment.)

My needs:
- I need to be able to keep better track of the site, files and changes to files - Version control!
- I need to be able to ask someone to help me with the site, but not have the worry of giving them full access to everything if they don't need it - Security! (I can't help but be a little paranoid)
- I need to be able to see what work has been done by the someone helping with the site. Which I think comes back to... version control.
- It would be nice to be able to couple the above with a more streamlined way to work with the files. So when working on something, I could edit file, save work, but separately push the edits over to the live site, at a time of my choosing, and equally roll back changes if I change my mind.

Ideal outcomes for me:
- I'm not in a position where I can justify setting up a super-doper dedicated systems here at my home-office to help with this. Ideally, this would all be managed externally, or at most with a program running locally on my main (Windows) computer.
- I want to be able to easily ask others to help with the site, but also maintain control on what access they have and the ability to track the changes they make.

Obviously, in my limited research, Git seems to do much of what I'm asking, but I'm a bit hazy on the detail and how far it will go towards solving all my problems, esp. on the access issue.

With the recent news about Pantheon, I had a quick look at that. Maybe that could be ok for me developement wise, but as I need to run some custom software on the server once it goes live - it might not be the right solution for me when that time comes, which puts it at a disadvantage for me. But also, I would like to remain host agnostic, generally speaking.

Bonus Question! I'll tack a little question on the end here. I thinking of using some of the e-freelance/oddjob sites out there to get help with some of the more mundane stuff to be done. What's the general consensus on that type of thing? Has anyone here posted small jobs to those boards before? How did it go?

Thanks for all your help.
Miles