I found this tutorial a few weeks ago and when I found a free pair or cords I decided to make it. I modified it a bit since I had to dismantle a pair of pants but the concept is the same, my skirt just has a few more vertical seams than hers and my flowers are much more basic. I recommend this if you are learning how to sew for your kids. The shape is very forgiving and corduroy is ideal for a play skirt so it doesn't matter if it gets beat up.
If you sew and have boys you should check out this website. She dedicated a month to boy projects. Some are difficult but most are manageable for someone who is learning.