Adding a public network to a private network.

Hey guys i have a very basic setup but need some information on how to add a public network to my private network.

I current have a D link router that is setup as a private network.

Example... I.P address of PC 1.1.1.10, Subnet Mask 255.0.0.0, Gateway 1.1.1.1, and DNS 1.1.1.1

I have DHCP disabled so if anyone wants to join the network they have to put a static I.P in the network range.

Now what i want to do is add a 2nd router but make it a public network. Just so it gives out 192.168.0.x.... I will like to have DHCP enabled so anyone who gets on the wireless or wire will pick up an I.P automatic. How would i be able to do this? Thanks.