You will find some information to help you walk through a personal audit at this site:
The end of the article provides guidance on how to protect yourself.
My best practices:
- Strong complex passwords for WPA-2 (Uppercase, lowercase & numbers, etc...)
- Strong admin password for your AP. Repeat it twice to make it longer.
- Limit your broadcast range. I installed my AP in the basement and can barely get a signal past my front lawn.
- Hide your SSID broadcast.