If you've never done "human subjects research" before or gone through the Institutional Review Board, it's a great idea to get training and understand it in depth before you plan or engage in an educational research project.
That said, developing lesson plans for teachers to adapt and use in their own classrooms is not considered research, but is exempt under the Common Rule as a "established or commonly accepted educational settings". Teachers can invite guest speakers to their classroom, consistent with school or district policies. They can also adopt quiz questions or assessment tools you have created for their classroom.
Where your project may become research is when you want to collect data from students or teachers for your use in research presentations and publications, not simply evaluating whether the lesson was effective. Consult with the IRB or someone with experience conducting human subjects research to decide if your plans constitute evaluating the lesson (may be exempt) or conducting research in an education setting (not exempt).