Help! What is GitHub?

To use GitHub, you must first have a program called Git installed on your computer. It tracks changes in your code (version control).

To Install Git, follow these directions from Software Carpentry:

Click on "Next".
Keep "Use Git from the Windows Command Prompt" selected and click on "Next".
Click on "Next".
Keep "Checkout Windows-style, commit Unix-style line endings" selected and click on "Next".
Keep "Use Windows' default console window" selected and click on "Next".
Click on "Install".
Click on "Finish".

To Sign up for GitHub with an official USGS account, follow these directions:

From here, I reccommend using SoftwareCarpentry's Version Control with GitHub:

You can fly through it pretty darn quickly! They say it takes 2.5 hrs. If you don't have that kind of time today, see below.

The quick-and-dirty version:

note: this linked tutorial lets you practice these commands online, and prompts you if you mess up - RUN THROUGH THIS FIRST.

This will open a scary-looking GitBash terminal window (no GUI? The horror!). Don't freak out! Remember you look super cool with a command prompt on your screen.

Navigate to the directory (folder) that you want to track. To do that in the command line, you type cd to change directory.

Typing pwd and hitting enter will show where in the folder tree you are currently (short for print working directory).
Typing ls and hitting enter will list all the files in that directory. To see hidden files, use ls -a (short for 'list')
If you're in "Users/yourname", and want to access a folder called "Dragon Taming" in your Documents folder, you can type cd Documents/Dragon Taming (cd is short for 'change directory').
Alternatively, you can use tab completion; type cd Docu and then hit tab; the rest of Documents should fill in. Ditto for the rest of the path. This is a handy little shortcut, and prevents silly typos!!

Once you're in the directory you want to track, type git init. This initiates a tracking system for files in the directory (and sub-directories). However, you must tell it which files in there you want to track.
To do that, you type git add filename. Use tab completion to add filename, to prevent typos. This adds to staging area.
To store file in your local (your computer) version control, type git commit filename -m "message about what you did to the file"

This part is a little tricky - it will not accept the commit without a note about what you've done to the file. Useful for going back through different versions. Can be confusing if an error message pops up while commiting. Repeat for all files you wish to track, and eventually push to github.
The default editor in Bash is an old-school program called 'vim'. It's difficult to use; if you end up here accidentally, exit by typing Esc then :q! .
To avoid getting stuck in vim next time, either 1) remember to enter a commit message with -m "message about the changes I made", and/or follow these directions to re-configure Bash's default text editor.

Now your file(s) are being tracked by Git! Hooray

BUT: we still need to push them up to GitHub, to share with others

Push files to GitHub. Go to your GitHub page, and start a new repository (your github -> Repositories -> New).

Copy the code under " ...or push an exising repository from the command line" (git remote add origin blah blah blah)
Paste the code into your GitBash terminal window. Hit enter if needed. Read the happy little Writing Objects 100% success message.
Now, refresh your browser window on the github page. WOW, your files are there!! Amazing!

In the future, to push changes made on your local machine up to GitHub, use git push origin master. To get changes made by yourself in the online editor, use git pull origin master. Get in the habit of doing these regularly, so that both are in sync. Git knows which file was updated most recently, and will let you know if there is a merge conflict it can't resove. Hooray!