Q&A: IEPs and advocating for your child

I've had a series of communications with Ashaki, who has a 7-year-old son. His old school (a private school) told her that her son needed to be in "special ed" because he has ADD. He doesn't, however, have any of the symptoms of ADD (more than any other 7-year-old kid has focus and listening issues, especially around putting on shoes to leave in the morning). He's reading well above grade level (and reads for fun at home), but seems not to understand math as it was being taught by his teacher and tunes out in class.

They just moved, and he'll be going to public school in a few weeks. She doesn't want him to be marginalized at this new school.

It seems to me that her son has some specific issues around math and would benefit from some testing to see what those are and how to help him, and that he and she will be better off if she can get an IEP for him. (For those not in the US, an IEP is an Individualized Education Plan, and it lays out what a child needs to get an education equal to the one given to the kids closer to the median. Our laws guarantee each child equal access to appropriate education, so theoretically a district/school/teacher has to follow the IEP.)

So my questions for you all are:

How does Ashaki start? What's the first call she needs to make to begin the process of getting an IEP? (She's in NJ, if that helps.)

For those of you who've been through the IEP process with a kid, what advice do you have for her?

For those of you who had trouble or issues in school, what do you wish your parents had done or known? What would you tell Ashaki from her son's point of view?
For everyone not in the US, do your countries have protections for non-traditional learners? How do they work?