Newbie on circular needles

I’m knitting an earflap stocking cap and am using circular needles for the first time. I have just basic knitting skills. I’ve made both ear flaps, per directions, and now am supposed to cast on additional stitches without breaking the yarn from the second ear flap. I don’t know how to cast on without breaking the yarn. I’ve looked through all the beginner info on working with circular needles and don’t see this addressed, so I’m guessing it’s something simple I’m just not figuring out. Please help!

Go here and check out the videos for single loop or knitting on in the cast on section. one of those should work well for you!