A video for "picking up stitches" can be found about 3/4 way down this page
. The technique of picking up stitches is generally done along an edge but in the case of this scarf you are picking up stitches through
a piece of already knitted fabric, along a row in order to make the ruffles. You would insert your needle through the first stitch on the right hand edge of the scarf and holding the working yarn at the back of your work, pull a loop through to the front with your knitting needle. You would continue this along the entire row until you have the 33 stitches 'picked up'.
Knitting into front and back of stitch.....knit the stitch on the left needle but BEFORE slipping the original stitch off the left needle you will knit into the back of the same stitch. Doing this on every stitch across the row will double your stitch count. A video for this can be found on this page
Hope that helps.