What type of photography do you want to get into? There are multiple areas to consider:
wedding and portrait
modeling
sports
photojournalism
landscapes/architecture/cityscapes
animals
Craigslist is certainly one option. If you are looking at wedding or portrait work, take time to find local established photographers to see if they are hiring or willing to take on a volunteer. The same may be true for modeling.
Additionally, you may want to check out local photography clubs to see who is there and if there are pros or those who have businesses attending. One site that would give you a wide range of meetups would be from the fredmiranda.com site. The forum to look at is
this one.
As for sports shooting or photojournalism, I'd recommend talking with local news outlets and seeing if they need or want a photographer at local sport events such as high school games. You should also search the
Mentoring Program (http://www.nppa.org/professional_development/mentoring/ - broken link) that the National Press Photographers Association offers.
For landscapes and architecture, it's a matter of searching out architectural firms that are looking for second shooters and assistants. You can get information about independent architectural photographers
here.
Hope this helps. Good luck!