Also, look at other scripts and learn from them. Copy them and edit them. Learn logical operators, control structures, etc. Definitely take a look at the "Tips and Tutorials" section that the local gurus have so kindly contributed to: http://www.unix.com/tips-and-tutorials/

And...Practice, practice, practice, make mistakes, make some more mistakes, learn from those mistakes and have a bloody helluva FUN time in the process.