I start my squash seeds a bit differently from some gardeners. Instead of starting seeds weeks early, growing a little plant up, hardening it off, and then planting it out after last frost, I start my seeds a mere couple days before planting them out. I simply sprout my seeds by placing them in damp paper towels in a container for a couple days. When they've gotten about an inch of root growing out of the seed, then I plant them out.
This way I plant seeds that I know have germinated, which is always useful with saved seeds, or several year old seeds, both of which seem to be situations I put myself in often. This way I can pick the best looking sprouts, and plant the number I want. I've had really good luck doing this with Squash, Pumpkins, Cucumbers, Zucchini, and Melons.