Finding a job in the modern world is a much more daunting affair than it was back in "good ol days". You can't get a decent job in most cases with just a high school diploma and a four year degree might just get you a interview.
What a person needs today is either a Masters,a Phd or just the right amount of experience to get the job. If you do decide to go on for higher education it is a good idea to have exactly what you want in a career in mind.
The other option of course is experience. You can get this by either getting paid seasonal experience, internships or volunteering. I have recently added a new page to the Working for the Earth Site called Volunteering and Internships. On this page you will find links that will take you to state and federal volunteer pages for various agencies.
The page does not contain any links yet to internships as I wanted to get the page up and running with what I could. I will be adding more links as times goes on and as usual I always welcome input from the job seeking community on where they have found sites that will fit on this page.
Good Luck on your Job Hunt
Working for the Earth