You can have two dhcp pools but you cannot tell this client should select from pool A and this client should select from pool B. So all the clients you want to be in pool B give them fixed ip. But remember if any other client which was suppose to get dhcp address from Pool A, fix his ip to pool B then he'll be allowed.
So to avoid this you should either use Managed switch or go for vlan.
If you have all wireless devices, then setting up vlans is quite simple. Only thing then required will be device which can tag the clients. Most of the APs now a days come vlan tagging facility.
If you have desktops then you have to invest in managed switch.
I can help you setup vlans, incase you decide to do so.