The Options Institute is the educational arm of the CBOE. They offer a lot of free resources on trading.
On August 25th and September 1st, they will be offering a class on Long Boxes and Short Boxes. Although these seem to be for more experienced traders, there's lots of stuff for newer traders as well.
Link,
[The Options Institute | Cboe](https://www.cboe.com/optionsinstitute/)
