Procedural safeguards are the full set of rights parents have in the special education process, and also the name of the document that explains them. The school must give you this notice at least once a year, and at certain key moments such as your first evaluation or when you file a complaint. It is often long and dense, but it is a map of the protections you can use.
Inside it you will find your rights to look at your child's records, to take part in every meeting, to get prior written notice, to request an independent evaluation, and to disagree formally through mediation or a hearing. It also explains the timelines and the steps for each of these. Nothing in the packet is optional for the school — these are duties the law places on them.
Most parents never read the whole thing, and that is understandable. But it helps to skim it once so you know what is in there, and to keep a copy handy. When a disagreement comes up, the section that answers your question is usually already in that packet. If the language is hard to follow, you can ask the school to explain any part in plain terms.
General information and document preparation — not legal advice.