Expanded install instructions

Install-ZSH.md

@@ -1,5 +1,20 @@
-[Zsh](http://www.zsh.org) should be installed (v4.3.9 or more recent). If not pre-installed (`zsh --version` to confirm), follow the following step to make it work:
+### Zsh?
-+  1. Install with your package manager of choice (ie: `sudo apt-get install zsh`)
+
-+  2. Make sure it installed by running `zsh`
+Oh-My-Zsh is a framework for [Zsh](http://www.zsh.org), the Z shell.
-+  3. Make it your default shell: `chsh -s $(which zsh)`
+
-+  4. Log out and back in.
+* In order for Oh-My-Zsh to work, Zsh must be installed (v4.3.9 or more recent).
+  * Please run `zsh --version` to confirm.
+* Additionally, Zsh should be set as your default shell.
+  * Please run `echo $SHELL` from a new terminal to confirm.
+
+### Install Zsh
+
+If you need to, follow the following step to make it work:
+
+1. Install Zsh
+  * with your package manager of choice (ie: `sudo apt-get install zsh`)
+  * from [source](http://zsh.sourceforge.net/Arc/source.html), following [instructions from the Zsh FAQ](http://zsh.sourceforge.net/FAQ/zshfaq01.html#l7)
+2. Make sure it installed by running `zsh --version`
+3. Make it your default shell: `chsh -s  $(chsh -l | grep "zsh" -m 1)`
+  * Note that this will not work if Zsh is not in your authorized shells list (`/etc/shells`)
+4. Re-open all terminals and make sure it worked by running `echo $SHELL`.