If you're really jonesing to make the granola, go ahead and use the quick oats. It will work, but you'll have to watch them a little more carefully in the oven because they probably won't take as long to get toasted.

For next time: Old-fashioned oats will bake into crisp, golden granola. You'll get better clusters with quick oats (just like outta-the-box), but the trade-off is a texture that's more flaky-powdery instead of crisp, and unless it is baked until it's really toasted (nearly caramel-brown) it often tastes of raw starch.

Quick oats are steamed and rolled (read: semi pre-cooked) and won't work in granola. Old-fashioned rolled oats, as Susan G suggests, are what you need here, and if you eat oatmeal, they are nearly as fast to cook as quick oats anyway. And, as everyone agrees, the steel-cut oats won't work for this application. (Though adding leftover cooked ones to your favorite whole-wheat bread recipe is a revelation.) If you have limited pantry space, old-fashioned rolled oats are the item of choice--by far the most flexible of all the oat types.

Get some good old fashioned rolled oats. I prefer thick cut organic oats from a small natural food store. Quick oats are not only smaller, they are intended to practically dissolve, so they are precooked -- using them for granola may result in mush. Hold out for the good stuff.

Steel cut is definitely wrong. Quick oats (as I understand it, though I'm possibly wrong) are the same as rolled oats, but cut up into smaller pieces, so they should be ok. The granola will just have bitty pieces of oats instead of larger flat pieces.