Here's a bunch of brushes (Tool Presets) I've made for Photoshop, Download them here for CS5 or for CS1-CS4, there's a lot of them so just delete the ones you don't want. I usually don't draw digitally but I think it's fun to doodle, I recommend loading a layer effect with a paper pattern set to linear dodge and adjust until it looks good.
I did this drawing with just the "Pencil 2B", I didn't try so much to make it look realistic but to make the brush usable:
