I have always blanched squash (3 minutes)prior to freezing. Here is a good explanation of why vegetables are blanched prior to freezing:
What is blanching and why is it a must?
Blanching slows or stops the action of enzymes. Up until harvest time, enzymes cause vegetables to grow and mature. If vegetables are not blanched, or blanching is not long enough, the enzymes continue to be active during frozen storage causing off-colors, off-flavors and toughening.
Molly

One of my friends suggested cutting them into circles, putting them on a tray in the freezer, then after they're frozen putting them in freezer bags - this way you can take out what you want. I'm trying this since it's just me and I don't always need a big bag of squash.

I looked around, and read this on a site after instructions to blanch:

"Yes, you can certainly freeze it without blanching. The purpose of blanching prior to freezing is to stop the enzymes that degrade the flavor, it's not for safety. As long as you eat the squash within 4 to 6 months, the flavor should be ok. Freezing without blanching may reducing the sogginess of the of the squash, but I doubt that it will help much. Freezing ruptures the cell walls and that is primarily what causes the sogginess."

Here is a link that might be useful: How to freeze summer squash