I used to be a Learning Support Assistant similar to classroom assistant, but on a 1-2-1 basis with a child with special needs. I know that a lot of these jobs are filled internally and that is why you rarely see adverts for them, your best bet would be to see if you can get a job as a dinner lady (although they call them midday supervisors now) and keep your ears open and let it be known that you would like to be a classroom assistant and then when a vacancy occurs you are already known to the school etc, making things much easier. Also in the school where I worked we never had the budget for classroom assistants so Learning Support was the only option. Although what Buenchico says is correct about the contracts, most LSA's are on a temporary contract which means that should the child being supported leave the school or no longer needs support you have no job or it works the other way in that you only need to give a month's notice if paid monthly. As I have no experience of Classroom assistants, I cannot say what sort of contract they would have.