Not exactly accurate for the speducator type but alas, there is no "what I think I do" meme out there for us! Who wants to take the lead on that?
A co-worker passed on a document today with job descriptions of the most involved people in your preschool autism classroom. At least for our school system, this is the list of people who are in direct contact with the students on a very regular basis and what their roles are. The list is short and very simple but gives an overview of who does what in the classroom. There are many other things I would like to add to the list but those are specific to my classroom and I think that anyone could take this list and adapt it to what best meets their needs.
I also think it's important to note that the responsibilities of the instructional assistant are also 100% the teacher's responsibilities. For example discrete trial teaching, data taking, ...and toilet training/diapering (because we don't want them to have all the fun, now do we! :-).
Make sure you go over these responsibilities with the staff that work directly with your students so that everyone is on the same page about what is expected of one another. You should also note particular things that you want to see happen in your classroom that they might not know otherwise. This will facilitate a smoother working environment!