Most dough recipes don't give you options for kneading. Usually they're written for one type of machine or they're written for hand kneading. But those methods aren't set in stone. Most dough recipes can be converted from one kneading method to another; it's just a matter of changing a few things: the amount of time you need to knead and the order you add ingredients.
In my opinion, any recipe that tells you to knead for a specific amount of time but doesn't give you any visual cues isn't a good recipe. There are too many variables that affect the gluten development, so time is not the best indicator. Sure, you can give a rough estimate so someone knows if they'll be kneading for 30 seconds or 20 minutes, but precise timing is pretty much impossible. Kneading early in the process may be all about mixing and less about gluten development, so watching the clock is fine. But instructions to knead for 10 minutes before shaping a loaf is much less useful.
So, if you're relying on visual cues to tell you whether the kneading is done, converting a hand kneaded bread to the food processor method means that you should rely on your senses rather than the clock. It's helpful to have an idea of when to check the dough, keeping in mind that the food processor kneads much faster than you would by hand.
When you're kneading dough in the food processor, stop and check the dough shortly after it forms a ball. At that point, you can check the gluten development and make sure there aren't any bits of dry ingredients or wet dough that need to be incorporated into the main dough ball. Sometimes there will be dry flour or a bit of wet goop just under the blade or bits of stray dough too high for the dough ball to reach. Stir those into the dough before you continue, then keep processing in short bursts, maybe 15-30 seconds each. Check the dough each time to see if the gluten has developed fully and to let the dough rest and cool if it has become too warm.
When it comes to adding ingredients, the food processor makes it easy. Generally you start with all of the flour and similar dry ingredients (along with butter or oil) in the food processor bowl, including instant yeast, if you're using it. If you're using active dry yeast, it's common to proof it in just a small amount of the water—about 1/4 cup—and add it later as noted below.
Pulse the food processor a few times to mix the dry ingredients and break up the bits of butter or oil. Then you'll consider the liquids. With the exception of the proofed yeast in warm water, all of the liquids should be cold when they are added, to help keep the dough temperature down.
If you're proofed yeast in warm water, that goes in first, followed by the rest of the water or other liquids. All of the liquids should be added while the food processor is running, and as fast as the flour can absorb them. You don't want to add the liquid all at once, or you'll end up with a sloppy, sloshy mess that will take a long time to incorporate. When the dough begins to form a ball, it has enough moisture.
Food Processor Pros and Cons
Using a food processor is fast and efficient, and it makes kneading completely effortless. And since the processor is so powerful, you don't need to be concerned about salt making the dough harder to knead, or oil coating the strands of gluten—the food processor powers through everything without hesitation and creates a smooth, silky, elastic dough.
That speed and power also makes the food processor very abusive to any add-ins. Chunks of cheese can become shreds in no time, and even seeds and nuts can take a beating. So be sure to add anything you don't want seriously mashed at the very end—just gently pulse to combine. (Or knead in any additions by hand after the food processor has done the majority of the work.)
The speed and efficiency of the food processor also makes it a little bit harder to adjust recipes. Keep in mind that once the dough has formed into a ball, you're almost finished kneading. Trying to add more liquid or flour to correct the hydration at that point can lead to overheating or even overkneading the dough.