Squash are some hearty plants. And, there are loads of varieties. Any summer squash can be used in a squash recipe, so don't skip over a recipe just because it says zucchini and you have yellow squash or patty pan or another type. As long as they're summer squash (thinner skinned and in season in mid summer), then you're fine.
To grill sqaush, just cut in in long slices about 1/2 inch thick longways. Brush with oil. Add any seasonings you want. Toss the strips on the grill. Turn when they have black marks and cook the other side. Time varies depending on the heat of the grill and whether you like squash kind of crunchy or softer. Play around with it and see what you like.
There are more complex squash recipes for the grill. I'll share some of them later. That should get you started and with different sprinkle seasonings, you can get a variety of tastes.
If you still have loads of squash (and most people who grow it do), then check out my zucchini and squash recipes at Southern Cooking.