A few Git tips

Synchronize with remote branch (master) - fetch remote code and merge with local (git fetch + git merge)

git pull

Update local version to master branch

git checkout master

The process when updating your fork of someone else's repository is described here. Basically, fetch changes from the original repository (upstream):

git fetch upstream

Merge the changes into local master branch:

git merge upstream/master

Push the changes to your remote repository (on GitHub). Easiest way on Windows is to use GitHub application.