Lots of bright conversational fabrics are fun and interesting for kids. Google or Pinterest for I Spy Quilts for inspiration. You can use just one main focal fabric or several.
As others have mentioned- prewash fabrics, avoiding scented detergents and dryer sheets if any of the children have allergies. I don't use flannel as it tends to pill after washings. There are many simple patterns that children love- 6 inch finished squares alternating with 4 or nine patches, or another called Quick Strippie on Maryquilts.com. Choose fabrics individualized for each recipient, and use bias binding for more durability. If you need bits of certain fabrics- cats or transportation for example- just ask. I'm sure some of us can help! Have fun.