Not sure where you are working now, how many years' experience you have or if you've already explored this, but I always recommend starting with a PR agency. Big or small, you get a ton of experience in a variety of fields, industries and practices.
This gives you time to hone your skills and decide which direction you want to head, especially if you want to jump to the corporate side.
Many corporations also have specialist and coordinator positions that only require 2-4 years' experience, giving you an opportunity to work your way toward a manager-level job.
Most PR manager positions require at least 5-7 years' experience. I'm at a director level now, which I earned after about 10 years of experience (post-college). I got my start at an agency as an account coordinator, and worked my way up there for almost 5 years before "jumping the fence" to a manager job elsewhere.
No matter what job you're in, though. If you feel that it's not going anywhere, it's time for a change. Always look for opportunities to better yourself professionally. You may just need to take baby steps sometimes instead of strides to get there.
The PRSA's Web site is a good resource for job opportunities in the PR field that you might not find on the mainstream job sites: http://www.prsa.org/jobcenter/main/index.asp
So is the job center on the IABC's Web site: