Knowledge of the "law" is a good thing, especially when it may apply to the rights of your children. However, what one may read as "black and white" is more often than not interpreted differently by others.
The two Federal Laws written for disabled children, the Individuals with Disabilities Education Act of 2004 (IDEA) and the Rehabilitation Act of 1973, Section 504 are by in large clear cut. However, there are regulations that go with each which muddy the waters and both Federal Laws empower the states to adopt their own regulations. Even worse, the individual school districts within the different states have their own "policies". Beyond this, some school personnel have difficulty playing by the Federal rules and choose district policy instead.
Do you need a lawyer to protect the rights of your child?
Of course not! Nor, are you required to have an attorney at any point of a due process procedure. But, it's not a bad idea to have one that is familiar with special education laws. Most are not!
Is litigation the best route to take in getting what your child needs?
Litigation is the last resort, and I do mean the last resort! If you have thousands of dollars, and time to wait, by all means file a lawsuit. Non-confrontational, open communications between the family and school with a big dose of reason, will get you further and have a better impact upon your child than any lawsuit.
Below you will find links to both Laws!
Study them and be familiar with their content.