ihoss - if you have a mixed mac/pc environment, you should NOT be using DHCP. I went through many problems until I made that change. Statuc IP's are almost a necessity as OSx macs seem to want to grab other IP's being used by other PC's on the network. This causes conflicts which a residential grade router will always have problems (see: slowness) recovering from. I've gone through this problem with several different brand of router (linksys, netgear, etc.)

For DNS server, each machine on your network should have your router's IP set as their DNS server, while the router should have the public DNS (preferably the one that your ISP provided to you) as it's DNS server. This way, you have a single point to change if your DNS ever changes. Your computers will always contact the router for DNS service and the router will always know to send that request off to the same place everytime.

RH