I had a solid coffee-shop/work session the other day. The one where you have no stress from making a deadline or producing a particular product. It was awesome to cruise around the web and explore resources at my whim.
One online destination was a video on project-based learning. I enjoyed watching the video because it was simple and succinct. It was created by Common Craft, which is a video publishing house that uses simple hand cut outs and a whiteboard to teach topics ranging from electing a US president to creating a Wiki. The videos are short and authored with teachers in mind. A solid resource for you and your kiddos.