The best lesson plans are always ones created by the teacher; having the deep knowledge of a work that allows one to customize a lesson plan for it gives both the students and the teacher better understanding and greater satisfaction. However, if there is not enough time to read the work and write the plan, there are other options available.

For The Three Questions, by Jon Muth and based on the parable by Leo Tolstoy, the work is short enough that a lesson plan should be easily created. The three questions in the title are the same as in Tolstoy's public domain story:

1. What is the best time to do something?
2. Who are the most important people?
3. What is the right thing to do?

In this case, with the information in the links below and the questions themselves, there it should be easy to write a simple lesson plan so students can internalize the work and understand how meaning and intention affect daily life.

For faster help, or a model on which to base your own personal lesson plan, here are some other resources. This page has a lesson plan that uses The Three Questions. Page 19 in this PDF file also has a simple lesson plan.

We do not know what age group your lesson plan should be for, and activities would vary to some degree for different age groups.  I checked around a bit, but I have not found a lesson plan on-line anywhere.  One activity that comes to mind is to have the students answer the questions themselves. They could then combine in groups, discuss their responses, and then vote answers for each group.  Other activities might include some research on the author or some activities involving parables in general.  An assignment to write a parable might be good, depending on the ages of the students.