Q:

github ssh keys: do we need just setup authorized_keys instead of id_rsa.pub & id_rsa

I am able to access the github servers thought ssh.
(somenv)bob@somenv:~/.ssh$ ssh -T git@github.com
Enter passphrase for key '/home/bob/.ssh/id_rsa':
Hi Bob! You've successfully authenticated, but GitHub does not provide shell access.

Here are my files:
(somenv)bob@somenv:~$ ls -ltar .ssh
total 24
-rw-r--r-- 1 bob bob  884 Aug 11 14:30 known_hosts
drwx------ 7 bob bob 4096 Aug 11 14:37 ..
-rw------- 1 bob bob  413 Aug 11 14:46 id_rsa.pub
-rw------- 1 bob bob  413 Aug 11 14:47 authorized_keys
-rw------- 1 bob bob 1766 Aug 11 14:48 id_rsa
drwx------ 2 bob bob 4096 Aug 11 14:48 .

The authorized_keys is a copy of id_rsa.pub. When I remove the id_rsa.pub and id_rsa, I cannot authenticate with github. Why not? In other words, how do I get ssh to pass authorized_keys to github? 
I am trying to deploy my ssh keys through this gist.
Here is my local environment:
 (somenv)bob@somenv:~/.ssh$ uname -a
 Linux somenv 3.9.3-x86_64-linode33 #1 SMP Mon May 20 10:22:57 EDT 2013 x86_64 x86_64 x86_64 GNU/Linux

A:

You only need your private key to connect to a remote server, this key is usually named id_rsa in the folder ~/.ssh.
id_rsa.pub is the public key component which you supply to github, and authorized_keys is the file that has all keys that are allowed to connect to the local machine on this account.

