Update intro.md

new_basic_shell/intro.md

@@ -49,5 +49,26 @@ No installation requirements.
 [GitBash](https://git-scm.com/download/win)
 
 
+#### Information on the shell
+
+shell cheat sheets:<br>
+* [http://fosswire.com/post/2007/08/unixlinux-command-cheat-sheet/](http://fosswire.com/post/2007/08/unixlinux-command-cheat-sheet/)
+* [https://github.com/swcarpentry/boot-camps/blob/master/shell/shell_cheatsheet.md](https://github.com/swcarpentry/boot-camps/blob/master/shell/shell_cheatsheet.md)
+
+Explain shell - a web site where you can see what the different components of
+a shell command are doing.  
+* [http://explainshell.com](http://explainshell.com)
+* [http://www.commandlinefu.com](http://www.commandlinefu.com)
+
+Software Carpentry tutorial: [The Unix shell](https://swcarpentry.github.io/shell-novice/)
+
+General help:
+- http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html
+- man bash
+- Google - if you don't know how to do something, try Googling it. Other people
+have probably had the same question.
+- Learn by doing. There's no real other way to learn this than by trying it
+out.  
+
 *These materials have been developed by members of the teaching team at the [Harvard Chan Bioinformatics Core (HBC)](http://bioinformatics.sph.harvard.edu/). These are open access materials distributed under the terms of the [Creative Commons Attribution license](https://creativecommons.org/licenses/by/4.0/) (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.*