Mass mailings doing work. And for large firms, those jobs are probably already taken by people who sent out materials on 12/1.
For all other employers though, you need to get to work asap. Get your resume together. Start researching firms. Try to write targeted cover letters for firms and employers you are really interested in (not just, "I like your X law practice," but something that really shows you're sincere interest and that you've put time in to research the firm). If you have any contacts at the employers or if anyone recommends you send a resume somewhere, make sure the recommender's name is at the beginning of your letter.
If you know an area of law you're interested in, see if you can find alums from your law school that practice near by and work in that field. Set up informational meetings (see if they can grab lunch or coffee with you) and start making contacts. DON'T ASK THEM FOR A JOB.
Then, send out a mass mailing to all the firms you can't write a targeted cover letter for (but don't expect overly much from these).
And I highly suggest Kim Walton's Guerrilla Tactics for Getting the Legal Job of Your Dreams. I used that book a lot last year and even more this year for OCI. She has tons of good tips on resumes, cover letters, how to get interviews, how to network, etc.