marytheres, the group in our area provides their services for free - they are funded by Federal Grant $. I have read online about people hiring advocates, and I think that when you have to hire an advocate it has the potential to be expensive.
What I did was look at the yellow pages link on the homepage at wrightslaw.org, it's organized by state, and I found the group there and I called them and asked the questions I had. They also have a website that has a lot of info about their services and who to contact. In our area the person you ask these types of questions to is called a "parent navigator", and even though the group's office is located in my city, they employee parent navigators that cover other areas of our state.
The advocate service truly, truly was THE one thing that was most helpful to me (other than having the neuropsych report) when advocating. I benefited so much and learned so much researching online and talking to local private professionals re specific challenges that ds had, but when it came to advocating at school, having the ability to talk to an advocate who understood the law and who'd worked with other families dealing with similar issues at the very same schools was extremely helpful.
There were other groups I found through wrightslaw that have been helpful also - one is an AT support group that deals primarily with adults who don't have access to AT through school services, but they were very generous in helping us out with advice even though our ds is in school (much more generous and helpful than the school district's AT folks lol), and there is a disability law group which helped with a bit of advice when we hit the proverbial brick wall with our school. So it's worth a quick look just to see what's listed for your area!
polarbear