git remote - Git push error: "origin does not appear to be a git repository"

Question

I am following the instructions given here to create a Git repository. All went well until the last line:

$ git push -u origin master  

fatal: 'origin' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

I'm using git version 1.7.11.3 on OS X 10.6.8

$ git remote -v  

returns nothing

Config file for the repository:

[core]
repositoryformatversion = 0  
filemode = true  
bare = false
logallrefupdates = true  
ignorecase = true  

I've had to open sudoers file using sudo visudo command and add the following to it (under # User privilege specification):

git ALL=(ALL) ALL.  

Now if I do:

$ git remote add origin /Volumes/500GB/git-repository/myproject.git  

it comes back with no error, but I don't see any code in the repository (it has the aforementioned directories like branches, hooks, ...)

If I do:

$ git push -u origin master  
fatal: 'origin' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

$ git remote -v   
origin /Volumes/500GB/git-repository/myproject.git (fetch)     
origin /Volumes/500GB/git-repository/myproject.git (push)

Answer 1

As it has already been mentioned in che's answer about adding the remote part, which I believe you are still missing.

Regarding your edit for adding remote on your local USB drive. First of all you must have a 'bare repository' if you want your repository to be a shared repository i.e. to be able to push/pull/fetch/merge etc..

To create a bare/shared repository, go to your desired location. In your case:

$ cd /Volumes/500gb/   
$ git init --bare myproject.git

See here for more info on creating bare repository

Once you have a bare repository set up in your desired location you can now add it to your working copy as a remote.

$ git remote add origin /Volumes/500gb/myproject.git

And now you can push your changes to your repository

$ git push origin master