Here is how I join stitches in the round when knitting on circular needles. You need to cast on 1 more stitch than your pattern calls for, you will lose one stitch with this joining method.
by All in the folds - Book folding
by LoomaHat.com
by Tuteate
by EasyMeWorld
by DrawingWiffWaffles
by Bronzepony Beaded Jewelry
by Maqaroon