I found lots of videos on YouTube about double knitting. Here's one that shows how to start a row and do a chart: http://www.youtube.com/watch?v=LckHV6LAGaw
It's actually video 2 of 3, by the way. She doesn't slip the first stitch (she knits it), so you might want to look at some of the other videos if you think the first stitch really needs to be slipped. (I would think, though, that you would just slip the first two stitches--one of each color--off the needle together. Then continue with your chart.)
There are lots of cast on videos, too, if you look up "double knitting."