to be in Resource Rooms to enable them to also take part in instruction with their peers (as role models) in the General Education classroom. For a RR Teacher, this necessitates that the RR Teacher be extremely flexible with the student, with the rest of the teaching staff and with the parent's of the student. The student's are unlikely to have the same cognitive level, social ability and work ethic in a RR placement and also in so called self-contained placements. So I will say again, the notion of only teaching high functioning Autistic kids in specialized programs is not likely and competition will be stiff. Having said that, there is more of a demand for Teachers with the ASD certification provided they are capable of handling the classroom management piece. Even IF you encounter a teaching experience with all kids with Asperger's, be advised that most of the kids have S&L, neurobiological issues and in some cases, cocurrent emotional disturbance.
To work in the field of education you must, and I mean must, be able to work and function in a team manner. If that is not your strength for any reason, then you will need to re consider some of your goals. These are tough jobs. Both private and public school units have demands that you will need to meet. On top of balancing all of the paperwork needs on time.
As to the lesson plans, first permit me to point out, that your mentor teacher in a placement is not your co-worker. She/he is your teacher. And if that party decides that you will write your own lesson plans for her/his review, then that is what you do.
Good luck with your plans but be prepared to change them. Education is going through huge changes at present and that factor will continue for the next ten years at least.