Network Design Project

I have a project to redesign our network, starting at our DSL connection and working inwards to the firewall, switches, etc. I am quite familiar with network design, but would still like some more information. I am wondering if anyone knows of some free resources (ie web sites) that discuss web design and security (other than Techrepublic). I am looking for guides on best practices concerning network design, security, etc.

Thanks for any information you can provide.