[The following is from an email to a student inquiry on PMP and CAPM I thought pertinent enough to share.]
There are two PM certifications that our course prepares students for. The primary one is the PMP or Project Management Professional certificate from the PMI® (Project Management Institute - www.pmi.org). In addition to 35 contact hours of project management training (our course), there is a qualification requirement for the PMP of 36 months hands-on PM work totaling at least 4500 hours if you have a BA. If no BA, it's 60 months and 7500 hours. The application is fairly thorough (long), and they do random audits, etc. The PMP certificate is roughly equivalent to a CPA (Certified Public Accountant - IMHO) certification. The exam costs $555 ($405 if you're a PMI member), is 200 questions and 4 hours long after you qualify, and it covers a broad spectrum of project management and general business knowledge.
The second is the entry level certification. It is called the Certified Associate Project Manager (CAPM) and only requires a high school diploma and at least 23 hours training experience. Qualification is much more relaxed, basically if you go through the training you would be qualified if you have a HS Diploma. The exam is 150 questions, $300, and focuses on the project management principles and practices of the PMBOK Guide (PMBOK = project management body of knowledge, usually pronounced pim-bahk).
Our course covers the training for both certificates. It's more than is needed for just the CAPM, though there are a couple benefits versus taking just a straight CAPM preparatory course. First, eventually you would probably go for the PMP, and the 35 hour training class qualification does not expire. So as soon as the experiential component of the PMP qualification is met, you've already got the training component satisfied and you could apply. The next benefit is that you will receive a broader exposure to all the practices of project management with the result you'll be a more learned (and I think better) project manager. Not a bad thing.
It is pretty much a personal choice. Project Management is one of those professions that you can actually do for 30-40 years and not get bored. The diversity of types of work is almost infinite. I cannot think of a company in any discipline that does not have multiple projects running somewhere in the company just about anywhere in the world. Another nice benefit of the PMI's certificates is that they are acknowledged, recognized, and desired globally - you can take it anywhere and it will be respected. The basic principles of the PM standard are universal.
Frankly, I have literally dozens of certifications in technology and business, and more than several college degrees. Please don't misunderstand, they all have their value, but if I were applying for an $80/hr PM job and up against a PMP with 10 years experience versus having an MBA and 10 years experience, the PMP is more likely to get the job, and more likely to get the premium salary.
Here are some links to the PMI's handbooks on the CAPM and PMP certification processes. They are required reading if you decide to pursue the certification as there are questions on the exam from their content.
The CAPM Handbook - http://www.pmi.org/en/Certification/~/media/PDF/Certifications/pdc_capmhandbook.ashx
The PMP Handbook - http://www.pmi.org/Certification/~/media/PDF/Certifications/pdc_pmphandbook.ashx