Editing Toolbox Theme

I am new to wordpress, html etc and have decided to throw myself in and start learning code by creating a child theme of Toolbox which is an empty framework that someone suggested gives you a good head start on creating your own theme.

Can anyone suggest any good customisation tutorials with a step by step of how to customise each importat part, eg. menu position, background, etc. or just any useful tips would be great. I have got firebug and I am using it to try and learn code by looking at websites I like.
I want a horizontal menu but I don’t know hwo to edit the menu?