I have two computers that connect to the internet through a wireless router. I would like to be able to SSH to them from my school. I set up my router to forward any port 22 requests to 192.168.1.100 ...

I assume you are trying to remotely connect to each PC from the WAN side as nothing has to be forwarded if doing it from the LAN. You will have to change the port used on his machine for RDP (and then ...

Your router can do all this—and your ISP doesn't want you to know ...