Additional advice, from someone else who has been through a mass layoff: Come out the gate swinging - your first 7-10 days are critical, though it may take three to six months to line something up.
But within the first 36 hours it may behoove you to begin informally tapping your network of people at potential employers to get yourself on their radar.
For a few reasons:
1) If you intend to stay in the same career, you will very likely be competing with other displaced folk with similar skills. You want to get out front of them, as cut-throat as that sounds.
2) People will also be sympathetic to your plight. Take advantage of this dynamic while it lasts.
3) These conversations can also be an opportunity to exhibit your grit, drive and good character : traits desirable employers value. Be genuine, but optimistic I.E. Don't over-mourn and DO NOT SLAG OFF on your former company I.E.: "I'm devastated, obviously. It is a great company and I loved working there. But I've also always been a fan of your shop - I'd be very interested in coming over there. Could you keep me in mind if you hear about anything opening up?"
After this initial blitz: Be prepared for a potentially long, slow, psychologically difficult job search. Finding a new job - when you don't have a job - entails a lot of hurry-up-and-waiting. You put out your calls, you send out your emails and resumes. Then you wait. You follow up. Then wait some more. Your new job is finding a job. And a big part of that job is staying positive and not psyching yourself out.
Good luck!