Now that you understand how the technology works, this is your chance to put it together as a cohesive whole. This chapter is about developing software from the ground up, and because it is a small project, you'll be utilizing many of the techniques of eXtreme Programming.
With all the fanfare and drama of starting on a new important project, it's easy to mentally jump ahead and start thinking about how to do stuff when you should be trying your best to consider what should be done.
So put your computer away, forget about your logins, passwords, databases, and just for now you won't need PHP, either. Instead you'll be using a technology that humans have spent the last few millennia refining paper.
Yes, paper is technology. It's ubiquitous, inexpensive, readable even if wet, requires no batteries unless you're in the dark. The same media type supports both write-only, rewriteable, and color and black and white inks. When paper is cut into small index-sized cards they can be used quite nicely for representing your PHP classes, they are moveable, and they can be mounted on a wall, traded, stapled, clipped, sorted and stored.
In short, your design and development process depends just as much on social interaction, wits, and thousand-year-old technology as it does on computer hardware and software.