Hi,
You will have to configure, dial-peers on each router (pots - for local lines and voip - for remote numbers), check the basic configuration in this simple guide, it shall do it for you:
Router(config)# dial-peer voice 1 pots
Router(config-dial-peer)# destination-pattern 14085554000
Router(config-dial-peer)# port 0/0
Router(config)# dial-peer voice 2 voip
Router(config-dial-peer)# destination-pattern 13105551000
Router(config-dial-peer)# session target ipv4:10.1.1.2
http://www.cisco.com/en/US/products/hw/routers/ps221/products_configuration_guide_chapter09186a0080089516.html#1028705
HTH, please rate if it does help,
Mohammed Mahmoud.