I had the same problem years ago-came up with this solution, and have always had more squash than we could use ever since! Study the blossoms carefully. There will be some with a stamen covered in pollen-looks like a big fuzzy brush in the middle of the blossom. These are the male flowers. The female flowers have what kind of looks like several fingers pinched together. There really aren't a lot of insects that pollinate squash with any regularity, so you have to act like a bee-just take a clean finger and gather pollen on it by rubbing it on the stamen, then transfer the pollen to the middle of the 'pinched together' pistils(Spelling is shaky-)
rub the pollen in, and you'll soon have a squash. Just do this every day you see new blossoms-there will be more male than female, and they open at somewhat different times of the day, but you can carefully separate the petals and pollinate the females. The other good news is you can cross pollinate squash too, if you have more than one variety growing, as long as they aren't new hybrids. Hope it helps!