These sites are the ones most likely to help you find a job in Atlanta:
* Craigslist.org - http://atlanta.craigslist.org/
Craigslist is a giant online classifieds site, broken up by location. There are "jobs" and "gigs" (project assignments). Browse through the jobs, which are posted in reverse chronological order (newest at the top, oldest at the bottom).
Since each location is a really different site, the quality can vary dramatically, depending on what the people in a given location will tolerate. Craigslist allows people to flag postings that are spam or scam, but it still happens.
For some tips on using Craigslist, see Guide to Using Craigslist to Find a job - http://www.job-hunt.org/onlinejobsearchguide/article_guide_to_craigslist.shtml
* Indeed.com - http://www.indeed.com
This site is a central source for finding job opportunities listed. Indeed is an "aggregator" which collects jobs from job sites (like Monster, HotJobs, and CareerBuilder, but NOT Craigslist) as well as from employers, newspapers, etc., so you go to one central place to search for the jobs and cover more sites than you even know about.
I just did a quick search on "biology" and "Atlanta, GA" and there were 197 job found - http://www.indeed.com/jobs?q=biology+&l=atlanta,+GA
You can sort the results by full-time, part-time, contract, etc. You can also save your search to have results e-mailed to you even when you don't visit the site.
* Job-Hunt.org - http://www.job-hunt.org/jobs/georgia.shtml
Job-Hunt will help you identify possible employers and also job search networking and support groups to help you with your networking.
Job-Hunt has over 8,300 links to employers and job search resources on Job-Hunt, including over 100 job sites and employers specifically for Georgia - online classifieds from local newspapers as well as links to the various Craigslist sites, state and local government jobs, colleges and universities, the state Employment Offices, and many, MANY other employers.
Be sure to check out the job search networking sites where you can make connections with employers and other job seekers, usually for free or very low cost. The list for Georgia is here - http://www.job-hunt.org/job-search-networking/job-search-networking.shtml#georgia
The Fortune 500 companies are also organized by state, and there are many other carefully-selected resources to choose from on Job-Hunt.
Good luck with your job search!