Code.org starts from unplugged activities to very basic programming..using Blockly (see below) , a free block programming site
If you are working on ipads ....scratch junior may be the way to approach programming
Scratch is a free and very user friendly block programming site
Google CS first is a new site to talk you through programming using Scratch ( see below) a free block programming site
Creative Computing are teacher and student workbooks created by the Scratch team. They are completely free to download.