Our team is using Git and GitHub to coordinate our development. GitHub is an online hub for storing repositories of files that teams collaborate on. Git is "version control" software that keeps track of changes made by different team members, as well as older versions of the project. It also does a pretty good job of merging updates made by different people editing the same file at the same time. GitHub is simply and online hub for Git projects (hence the name), and it helps people find new projects to "fork" (copy) and/or contribute to.
I've been using Git & GitHub for some time (and wrote an article about how to use it to build and clone an online textbook), so I made a couple videos to help others on the team get familiar with the workflow. I'm posting them here in case others find them useful.
These videos assume that you are using a Mac, and that you have Git (and the Mac command-line tools) installed, as well as an account on GitHub already set up. (I'm getting a new computer in a couple weeks, and since I'll need to install all of that on the new machine, I'm waiting until then to make a getting-started-from-scratch video. The article linked above contains links to a lot of resources for getting started with Git, if you want to jump in now.)
So, without further ado, here are the videos!