This set of instructions was used successfully September 2014, with a group of 40+ students. We knew the OS for 35 of them, split evenly between Windows and *nix. Specifically, Mac (n = 16; 45%), Windows 8 (n = 12; 34%), Windows 7 (n = 6; 17%), Linux (n =1; 3%).
You might have changes on the remote AND on your local repo. Just because you don’t remember making any edits in the browser doesn’t mean you didn’t. Humor me.
Pull first. Resolve any conflicts. Then try your push again.
Do you have spaces in your directory or file names? I told you that was a terrible idea. Get rid of them. If that doesn’t fix it, I also highly recommend you have a more powerful Git(Hub) client installed for these situations.
We are practicing what we preach! This entire website is created with the tools and workflows described above. Go ahead and watch us work.
Long-term, you should understand more about what you are doing. Rote clicking in RStudio may be a short-term survival method but won’t work for long.
trygit is to (command line) Git as swirl is to R. Learn by doing, in small bites.
The book Pro Git is fantastic and comprehensive.
GitHub’s own training materials may be helpful.
Find a powerful Git client if you’d like to minimize your usage of Git from the command line.