David,
Welcome to KindleBoards!
I've cribbed a response from one of our resident experts here to try to get you started troubleshooting. Which kindle do you have, by the way?
Here's Morf's guide:
I'm assuming you know the SSID or network name for your network: here I'm going to call this the network name.
You also need to know your password or WPA Key. I'm going to call this the password.
Now do the following:
1) On the Kindle, Press Home, then Menu. From the menu pick settings.
2) In the Settings screen, go down to WiFi settings and pick "View". It might ask you to turn wireless on, pick OK.
3) After a few moments, it should list WiFi networks it's found. Look for the one that has the same name you've noted down for your network name. Select "Connect" next to this one.
4) It will then ask you to enter the WiFi password. Here you need to type in the password you noted above. Depending upon the type of Kindle you've got you either use the keyboard on it or the on-screen keyboard. check for capital/small letters, numbers, punctuation marks, make sure you don't get numbers and letters mixed up (I/1, 0/O etc), and look at each character as you enter it. Each character appears as you type it, then turns to a dot as you type the next one (so somebody watching can't read it easily). When you've entered it all press "Submit".
Hopefully that should be all that's needed, in a moment or two you should see "WiFi" and a signal strength bar at the top-right of the screen.
If this doesn't work, please let us know exactly where it goes wrong - do you not see your network listed, is it listed but your password is not accepted, or is something else going wrong?
Let us know at what point in the process you are having a problem...
Betsy