I did my student teaching in kindergarten. It's a win win, because if you child's kindergarten teacher is lucky enough to have a para-pro (in which their time was rationed to other K classrooms) then your teacher has an extra set of hands, eyes, etc available to small group and one-on-one teaching.
Also as other posters have mentioned, the student teacher is not left alone inthe room unsupervised.
The way my student teaching rotation worked was that I spent the first two weeks observing and assisting the tacher like a para-pro (handing out supplies, worksheets, helping students who were having trouble with their work), then on week three I took over the teaching of one subject, the next week I taught two subjects, the following week I taught three subjects until I gradually took over the classroom. We had a mandatory requirement in our program that we had to teach on our own -- whole day instruction -- for four weeks. As I took over more and more, the regular classroom teacher became my para-pro. I also had to design and teach a two week insturctional unit in a given subject about a topic.
Materials used for all my lessons were exactly what the teacher used. The school I taught at did a program called Saxon phonics and Saxon Math in which the teacher had guided lesson plans, so I used those. During small group reading instruction, the students read from selcted basal readers, but I could also expand upon a story and carry out a story over a week doing different reading activities.
Student teaching was no different than an actual job. We were required to stay an hour after school just like the teachers, and the minute I got home, I was writing lesson plans well into the night (as I took over more duties). Most plans would take an hour, but our lesson plans had to be scripted (word for word what we would say, with anticipated student repsonses DONT GET ME STARTED, as oppsoed to plans that say "the teacher will ask students," "Teacher and students will discuss..."
Ugh, that semester brought about so much anxiety I almost had a nervous breakdown. Espically when my college professor who supervised us, nitpicked me over every little thing (a typo in my lesson plan, improved prop that was not written into my lesson plan, being flexible and taking advantage of "teachable moments" that came up in student discussions). My supervisor was such a stickler for KEEPING TO THE PLAN, that the classroom teacher I was working with had to stand up for me and tell her to back off, and if anything teachers should be flexible in their lessons/teachng. Not everything goes according to plan.
OMG, just talking about that semester and the anxiety is coming back........