When I help someone through an "interesting" situation with git, there are a few concepts that very frequently come up. Sometimes, after covering these concepts, people come to their own solution or answer their own question. When we do have continued discussions, it's much easier because we have a shared context.
There is a plethora of existing git resources, but people have expressed to me that it can be difficult to determine which are the best investments of their time, or in which order to consume them.
Specific resources will follow, but I believe that conceptually the following path will have the most critical impact for how effectively you use git:
- Understand that git is a graph
- Understand that branches and tags are refs (pointers) to the commit nodes
- Understand the relationship between the working tree, staging, and the repository
- Understand the relationship between local repositories and the zero-to-many remotes
In my experience, after digesting these concepts, it is much easier to explore the commands and tools to apply the desired operations over those objects.
I cannot overstate how much impact Git Happens had on my understanding and thought processes around git. I had been dabbling with git (my teams were still using a lot of TFS and SVN), and this talk helped me build a proper mental model of what was happening.
To this day, when people ask me how I learned to think about git the way that I do, this is where I send them. In about an hour, you'll gain critical understanding of the four points above.
Go watch it! There's also a companion website.
If you prefer text over videos (or why not both?!), How To Teach Git is a fantastic resource which was recently shared with me. The illustrations here can really help things click.
This is covered in the Git Happens talk, but in my opinion it's worth emphasizing again.
On Windows, I typically tell a person I'm helping to pop up gitk and visualize the graph. After we talk through it, understanding and visualizing the graph is an "aha!" moment. I don't have a strong recommendation for similar tools outside of Windows, but I believe the git log --graph --decorate --oneline will be available at the command line on all platforms.
I like Git is a Directed Acyclic Graph and What the Heck Does That Mean? as an additional reference on this topic. There's also the Graphs and Git section of Think Like (a) Git.
Please feel free to use these. In my personal opinion, they're best used as reminders after you grok everything covered in the references above.
To quote Rachel,
They didn’t know the reason why those steps. They only knew that they should follow them in order not to get into trouble.
I would echo this, and I would add that in my experience, following the steps without knowing why can make a bad git situation worse. I've seen this when a person chooses the steps they believe apply to the current situation because the error message looks similar enough (or even identical), but they truly needed something very different.
My take on it: First, critically reason over the graph, the staging area, your working directory, etc. to determine what you want to achieve. Then, use the cheatsheets to remember specific commands, args, etc. to accomplish that result.
All of this said, I do very much enjoy ohshitgit, and I hope you do too!