No offense intended KiWiRay, but that link is not very helpful for a newbie. My first visit to your suggested URL left me in a circular loop on the Open Agricultural website. The closest thing to instructions is a video. There is a link referring to documentation but that just takes you to the GitHub repositories.
I consider myself a nerd, and have built many projects from scratch. The above link is making me think about turning in my techie card. The Build a Personal Food Computer link contains a great overview of the concept, but it lacks details.
Newbies: Please read http://wiki.openag.media.mit.edu/OpenAg%20Food%20Computer%201.0 before diving in. I found the Wiki a much better starting point.