Cisco 1800 Series Integrated Services Routers (Fixed) Software Configuration Guide - Configuring a VPN Using Easy VPN and an IPSec Tunnel [Cisco 1800 Series Integrated Services Routers] - Cisco
IOS Router as Easy VPN Server Using Configuration Professional Configuration Example - Cisco
Cisco IOS VPN Configuration Guide - Site-to-Site and Extranet VPN Business Scenarios [Cisco 7200 Series Routers] - Cisco