Just got laid off, what should I do first? (update)

I was let go as a payroll clerk this week and I am still in shock. Any experience at all would help. I have a box of my things and a short letter about benefits. What did you do in the first week?

Thanks for writing this out. I went through something close to it 7 months ago, and it got easier once I kept a simple log of every call and form.