I did just what Neo suggested to learn shell scripting in January 2013 and the 3/4 finished project has become huge.
He is correct though, just think of something you would like to do and jump in at the deep end; it looks daunting at first but you will get to grips with it sooner than you think.
There is plethora of info on the Intertwines and on here about shell coding and if you show you have tried to get things working stage by stage and enter some snags the guys on here will offer help voluntarily. Sometimes they show you what you think looks like _NOISE_ but as you get deeper into it you will begin to understand this _NOISE_ and you will use snippets of them for your future project(s).
Bazza.