Installation is quite idiot-proof and the kind folks at Parallels have made installation as simple and hassle-free as they could. I was able to finish my installation in about five minutes on my (ancient) MacBook Pro. Instructions were very clear and concise that no one should have an issue with it. Installation took about 500MB when completed and a restart was not needed.
Upon launching the program for the first time, you will need to either select the free 30-day trial, or key in the activation code and after that, the initial welcome screen allows you to create a new Virtual Machine (VM), migrate from another partition or just use a predefined VM. Everything is just like clock-work and it is pretty easy.