There are many job listing sites for customer service positions. An easy way to find several is to type "customer service jobs" in a search engine, such as Google. Other resources are:
Customer Service Jobs (http://www.customerservicejobs.com/) - Within this site, you can search for jobs, post your resume, and receive notices of new job listings.
Customer Service Jobs Net (http://customer-service.jobs.net/) - This is a site that allows you to post your resume and search for jobs by title or location.
Call Center Jobs (http://www.callcenterjobs.com/) - Lists jobs by title and responsibilities, allows you to post a resume, and to research companies that have job openings.
International Customer Management Institute (http://www.icmi.com/Resources/Industry-Job-Board) - This site has job listings, but most are for call center managers.
You can also search online job boards, such as Monster and CareerBuilder, for customer service jobs. Try the keywords "customer service" and "customer support" for the total listings.