Wrap and turn is a technique for doing short rows. There's a good article here -
Short rows - knitty.com and a video here -
http://www.knittinghelp.com/knitting...ed_techniques/ - scroll down to Short row with Wrap.
On the first slip, keep the yarn in back, turn and with the yarn in the back, slip the stitch onto the right needle. I believe you slip purlwise in both instances.
To count stitches for BO, you will actually be knitting 5 stitches, but passing the stitch over only 4 times (k2, pass 1st st over 2nd, k1, pass st, k1, pass st, k1, pass st).
When you come to the wrapped stitch, knit it together with the stitch it's wrapped around.