Teaching fractions, in my opinion, starts with symmetry. I just found a great song by Judy & David called "The Symma Tree" (it's available on iTunes for 99 cents), and it really explains the concept very well for pre-k and kindergarten students. I think cutting Play Doh in half is a great way to get started teaching the children about part-part-whole. It's easiest if you start with circles and squares. Next I get out the masking tape and put a line down the center of my body. The kids crack up laughing at first, but then they all want to volunteer to be the person with the line of symmetry down the middle of their body! I then play games like "Simon Says," but when we freeze, I ask them if they're symmetrical or asymmetrical. You can also use the song "Freeze Dance" by Greg & Steve for the same activity. I like to use slices of cheese, graham crackers, and candy bars to show children how you can cut things down the middle to leave two equal parts.
For fine motor practice, I had the children complete this symmetrical house picture. If you hold a mirror across the page you can show the students how the whole image should look, to help them draw the correct parts. I have many more of these; if you leave a comment that you like this one, I will put up more as freebies.
When you actually start exploring fractions, I have found two fabulous songs that I use all the time. The first one is by Dr. Jean and it's called "Fraction Pizza". When we sing the song, I use plastic fraction pizzas that I bought at a local teacher store. I've also seen velcro pizzas at Toys R Us. If you can't find these toys, you can just make an art pizza with markers on a paper plate. The second song that I like to use is "Fraction Is Part Of A Whole" by Miss Jenny, and it's also about pizza.
I made these books a few years ago when I was in kindergarten, and I hope they are helpful for you:
My Fraction Book
My Circle Fraction Book
Enjoy working with fractions!