There is no one way in. Every single person I have ever talked to found a different way to do it.
I am a DP, and I can tell you my road, and offer advice I've gotten from others though.
I went to film school (yeah I'm poor too... I'll be paying off student loans my whole life). I don't think films schools are for everyone, but mine was in the center of Hollywood, taught by people working in the Industry, and I honestly went for the connections. I worked on student films DPing and ACing, and when I graduated, I scoured Craigslist, Camerajobs.net, and Mandy.com. I took a lot of work for free, as an AC, before I met and worked with a DP that really liked me. He calls me back for a lot of paying gigs now, and then I worked another free film that lead me to a paid feature.
The trick is, work hard, be likeable, know your stuff, and ask questions. I would suggest going to your local rental house and volunteering or asking if they're looking to hire. There is no better or faster way to learn cameras than by working on them everyday.
Be willing to start at the bottom. Realize that it takes time to foster the relationships that will get you work. Also realize that you aren't going to join the Union right away. I'm not sure about the WGA, which houses animators (or are they actual a part of the Local 600... the camera union? I can't remember. They're tucked away somewhere odd) but to join the union as a DP costs around 12,000 dollars. Even if you join as a 1st AC (which I think is around 6,700) it's really hard to move up, and you have to pay again when you do. There are all kinds of ruless about what jobs and you can and can't work...
Check out their website: http://www.cameraguild.com/
And never give up. If it's what you want to do, DO IT.