Ditto to everything DeeDee and Sweetie wrote. You might be able to find out what your school district policy and procedures re 504 plans are online at your school district website.
Re pulling in other people, the principal and school psych might be a part of the process - there is an initial meeting in our district with many of the same tam members who would be pulled in for an IEP eligibility meeting - school psych, teachers, school 504 coordinator and in some cases principal.
Do you have parent advocates in your area? Not paid advocates, but one of the groups that is funded by Federal $? Our local group was able to provide us it's very quick over-the-phone (at no charge) when we were seeking a 504 for our dd. we found the group on the wrightslaw yellow pages.
Good luck!
polarbear
