Pick up and knit

I’m starting a side border in garter stitch on an afghan. It says, “Pick up and knit…” How do I do that since I had to cut the yarn from the end border I completed? I’m a beginning knitter. I appreciate any help I can get.

There is a video to demonstrate picking up stitches on the edge.

http://www.knittinghelp.com/apps/flash/video_player/play/166/1

Take the yarn end and begin picking up the sts as shown in the video.