Emulating film-processing techniques..

[Gottdammerung]

Was just wondering if anyone knew of any good books or online resources detailing the various experimental methods of processing film. I'm not too hot on this given that my photography has been strictly digital so far with only a couple of toes dipped in film in the past..

I'm aware of processes like bleach bypass, redline and cross-processing but was wondering if there were any more techniques used in the past that can could be of use for visual inspiration or for emulating digitally...

[PhotosGuy]

This was called stripping the negative/transparency: Using a Layer Mask to hide part of an image. Advantage is that the mask is reversible, where the effect of an eraser is not.
Need to remove a background from something? (http://photography-on-the.net/forum/showthread.php?t=82876)