Iron by example will assume that you have had a reasonable introduction to rust and cargo, such as reading the rust book.
It will help if you have previous experience developing web applications in other languages, as we won't be spending too much time covering the basics of HTTP and other such fundamentals.
You will need the latest stable rust and cargo releases to compile and run the examples here. I highly encourage you to follow along by typing out the examples, running them, and editing them to see how things work.