I'd be remiss if I didn't use the comments to mention the amazing and totally free, "Unix for the Beginning Mage". The author of the article also didn't mention this great resource. It's an amazing book and a short read. It took me about 3 hours to work through completely. www.unixmages.com
If you don't know how to use your shell, block yourself off an evening with this book and change how you forever use you computer.
If you don't know how to use your shell, block yourself off an evening with this book and change how you forever use you computer.