Pattern recognition in images

Any resources you recommend? Ultimately I want to write a face recognition program, but I'll write a couple of toy programs on my way there.

Do you have the basics of how images are stored and processed down?  By that, I mean, can you parse and read in a jpg or a PNG?
If not, I recommend reading up on the PNG library, since the library allows you to access the information in an uncompressed format fairly easily, and being bitmap it doesn't force lossy compression into an image, so you have less noise issues to worry about.