A good point of reference is http://www.microsoft.com/wifi as you'll find a wealth of best practise advice there. Another good source is the current TechNet Magazine which can be accessed both online (you can download the entire thing) and in print too in some geographies. The current (November / December 2005) edition includes an article written by Kathryn Tewson and Steve Riley titled "A Guide to Wireless Security" - they dispel many security myths and provide good practical advice. Simply browse to http://www.technetmagazine.com to see for yourself.
Thank you to everyone who joined my webcast earlier today that was titled "Wireless Security an Oxymoron?" - the session was recorded so you will be able to replay the audio (and slides) at your leisure - I'll post a link to the replay in the next few days as it becomes available.
If you'd like to secure your home wireless network then please take a look at a recording I made some time ago that SHOWS you how to secure both your wireless router and Windows XP machine - it's only 3:30 minutes long and takes you step by step through implementing WPA - that's a good start though clearly there are additional steps you may wish to take.
During the webcast I asked the audience to watch out for this blog entry and feel free to pose questions - just hit the "comment" button below this post. I'm very keen to hear from you (whether you joined the webcast or not) to find out what troubles you with regard to securing your wireless infrastructure - what pain do you experience? I'll post suggestions of how to alleviate problems wherever I can.