This is not anything to do with a location setup or where you use your iBook, but the IP address.
These web sites will look at your IP address and from that it determines what part of the world or state (county) you are in. You would need to change to proxy server details in preferences > network or create a fix IP address on your router.
You're best to web search on something like 'Change IP address Geographical Location'
Best of luck
You nailed it... I went to the web search for instructions and found out why the address comes up as Maine: the RoadRunner host name's web address says "maine.res.rr.com" and is located in Windom ME. Hence the stores in that locale show up as my local stores. The website I went to (WhatIsMyIPAddress.com) also suggested at ways to adjust the address but I am not going there just yet. I'll read up more on the subject, and try it later. But now I know why I keep ending up in Maine! Thanks for your help/