Chances are that if you're reading this you understand what GIT or GITHub is all about and naturally we use it and enjoy its benefits. Despite the name [and it's not an acronym] we like to keep things as relatively simple as possible and with our dear friend GIT the old aphorism of Too Many Cooks applies and let's not make GIT into a project within itself.
Because GIT was built for developers there is a myth that we all love the command prompt and live off Coke-Cola and pizza. Neither are true and thankfully GIT has a very fine GUI called SourceTree and we use this [as well as the command prompt which, to be fair, is faster].
We prefer bitbucket.org rather than github.com but that's just because you get some FREE private repositories with bitbucket; the two platforms are almost identical albeit big sister has a few extras which a very small number of developers might use. Both work.
Agencies and Developers are always invited to join our private repos - just drop us an eMail. We also run .ssh [BitVise] for FTP and a very good [and very fast] product called FileSync which is great for local and staging development.