Homeschool conventions can be a great place to learn about different teaching methods and techniques. The Teach Them Diligently Convention had a series that focused on getting started with unit studies:
The first post in the series explains what unit studies are and a general idea of what it could look like to use them in your home.
The second post shows you how you can teach the same subject to many different ages and levels of children. This is a great option for large families to help cut down on the amount of teaching material you need to buy. There’s even a post that shows what a day of doing a unit study could look like in your home.