Join on circular needles

[jelyapt]

I am a novice knitter trying to tackle a pattern for a diagonal lace cap. The instructions call for me to cast on 80 sts, knit one row then... join. I don't know how to "Join."
:( Can anyone explain this step to me?
Thanks.

[Ingrid]

When you join the knitting with circular needles, you just start knitting in the round. Have your working stitch with the yarn strand on the tip of the right needle and the first stitch that was cast on on the tip of the left needle and just start knitting.

http://knittinghelp.com/knitting/advanced_techniques/

There's a video here.