The Ancient Egypt site from the British Museum could be a spine for a complete Ancient Egypt study. It lists the major topics to study (geography, pharaohs, daily life, etc.) and each topic has a Story, Explore and Challenge. There is interactive text, with lots of pictures of artifacts from the Museum. The interactive parts and games are very well done. You can find out what life was like for a rich Egyptian, or play a game of Senet. Add in a few library books, a couple of documentaries and a fun art project, and you’ve got a unit. Suitable for upper elementary through middle school. Completely free.