Yarn overs are my discovery this year and I love them. They make for much faster knitting and lend themselves to lots of patterns! If you have done garter and purl you can definitely do yarn overs and knit two together.
Here is an easy 'how to" that shows the pictures.
Simply take the yarn from where it is anchored on the right of the stitch on the right need under and wind it around over the top of the needle and do the next step (which will probably be knit two together or knit 1).
I nearly kicked myself that they were so easy and I had hesitated for so long.
Don't hesitate for as long as I did.