Laid off this week, where do I start? - any advice?

They called a meeting on Tuesday and 18 of us were let go. I had been there 18 years. This is my first time dealing with any of this. I have a box of my things and a short letter about benefits. Is there a checklist I should follow?

Thanks for writing this out. I went through something close to it 3 months ago, and it got easier once I kept a simple log of every call and form.