See POST 17 of our forum sticky to see a common setup where we use the second router. You can do that with POST 17 at http://forums.cnet.com/5208-7589_102-0.html?forumID=62&threadID=264135&messageID=2584349&tag=forums06;forum-threads or think about a double nat (which I will not write about at length.)

In closing, do not share your printers, disks on any WEP system. There is easy to use software that connects to WEP and MAC filtered WIFI spots without too much work in about 2 minutes or less. Then means it's about as secure as the security seal on an aspirin bottle.
Bob