OpenVPN is a full-featured open source SSL VPN solution that accommodates a wide range of configurations, including remote access, site-to-site VPNs, Wi-Fi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls. Starting with the fundamental premise that complexity is the enemy of security, OpenVPN offers a cost-effective, lightweight alternative to other VPN technologies that is well-targeted for the SME and enterprise markets.
This page is designed to provide an applied-level of support. OpenVPN HowTo has lots of great examples and configuration option.
Help with creating a VPN which connects multiple lans. Server and clients have lans behind them. This will help you understand how to use the route, push route, and iroute commands.
For instruction on setting up an OpenVPN server on FreeBSD, see OpenVPN Server