Any monitor with a HDMI input should work with the Raspberry Pi. If your monitor has a DVI input, a HDMI to DVI adapter will be required.
I bought a used Dell monitor and I use a DVI --> HDMI cable to connect to my Raspberry Pi. You should look into a powered USB hub. The Raspberry Pi's power supply may not be sufficient to drive all USB powered devices.
Also any starter books that would be suitable as both parents are
stupid.
You are the smartest parent because you bought a Raspberry Pi for your son. I don't know your son's age. The Raspberry Pi has got a scratch programming interface especially to teach programming to kids. If your son has some basic programming experience, this book might be helpful to work independently.