@johnpoz:
Yes isolate them to their own vlans.. Limit what they can do into your other networks, limit what they can do outbound to the internet. And most likely not allow any unsolicited inbound.. For example if you have camera's and you want to to view them while your remote.. VPN into pfsense and view them that way.
You most likely will also want to log any outbound traffic they might be doing and you allow. Or even what you are blocking - why is that camera trying to talk to an IP in china for example.
You may want to create different vlans for different types of iot devices, etc.. Comes down to what exact iot devices your installing.. And what their connectivity needs are. If you wanting say camera's to upload video to the cloud - prob want to lock that down to only allow them access to the official networks for that, etc.
Pfsense is great for doing this.. But you will most likely want vlan capable switches and wifi so that you can isolate both wired devices and wifi devices to their own vlans.
Thanks for the detailed response Johnpoz! Echoed a few things I had heard and read, which I will be applying. I will post an update of the set up once I get all the devices figured out. Like you pointed out it all comes down tot he exact devices being installed, so i'm going to finalize those first but my security cameras are the ones I want to pay the most attention to, especially because of some of their default plug and play features.