In order to know where federal job vacancies are, you may contact the following publications, which publish job vacancy listings:

Federal Career Opportunities Report
Biweekly
Federal Research Service
7360 McWhor Place, Suite 201
Annandale, VA 22003
800-822-5627
(703) 281-0200
(Federal Jobs Central)
http://www.fedjobs.com/

Federal Jobs Digest
Biweekly
Breakthrough Publications
310 N. Highland Avenue
Ossining, NY 10562
800-824-5000
(914) 762-5111
(FJD Hotline)
http://www.jobsfed.com/

Federal Times
Weekly
6883 Commercial Drive
Springfield, VA 22159
800-368-5718

Federal Research Report
Weekly
Business Publishers
951 Pershing Drive
Silver Spring, MD 20910-4464
(301) 587-6300