Luanne, can you see calibre from your netbook?
I agree with theducks -- your setup seems much more "advanced" then most.
When you connect the tablet to your wifi network, what program is asking for the password? Is it a browser, or is it the wifi connector itself? If the process is:
- turn on wifi
- bring up a browser
- attempt to go to some web site
- get asked for a username & password
- then get to the web site
then the browser is probably authenticating directly with the router. This won't happen when you are talking to calibre. The fact that the router asks for a user name implies strongly that this is what is happening, because normal wifi authentication uses only a password. I have no idea how to turn this "feature" off.
The "URL number" (the IP address) to use is the one reported by ipconfig on your main PC. The router will have a different one (usually ending in .1), as will your netbook. These other IP addresses aren't useful.
You can get your tablet's IP address by going to settings, wifi, and tapping on the connected network. You should get some data about the connection, such as speed and (ta da) the IP address.