Whats the best way to get a job with the National Park Service?

I’m a sophomore in college and my major is history. I was just planning on teaching it, but my friend (who is also a history major) told me that he is going to get a job with a National Park and I thought that was a great idea. So, if anyone out there works for the National Parks or knows anything about starting a career in one I’d really appreciate it.

The NPS has approximately 16,000 permanent employees and hires up to 10,000 temporary and seasonal employees each year. Additional support is provided by 125,000 volunteers annually.
For Permanent Jobs with the National Park Service,Vacancy announcements are posted at http://www.usajobs.gov/ , the official employment website for the United States Federal Government.
For Temporary jobs, visit
http://www.nps.gov/personnel/seasonal.htm