Can I lock into my airport only?

Whenever I put my MacBook to sleep and restart, it seem that it find my neighbors wireless, which inevitable drops the signal (and I don't think it is secure.) Can somebody tell me how I can set it to only find my network? (90% of the time we use this just around the house - resetting to find any wireless on the few occaisions we go out is preferred over setting it to my Airport many times throughout the day...

I'm now running a brand new Airport Extreme.

(And apologies if this is posted elsewhere - point me to it. Tried to find the answer, and couldn't...)

Thanks!