b/w photography, any advice?

[Digital Matt]

Use a channel mixer adjustment layer, check grayscale in the bottom left, and play around. Adjust it to suit your taste, always trying to keep the percentages equalling 100% in some manner.

Another interesting way to see the effect of color on BW is to make two hue/sat adjustment layers. On the topmost layer, put the saturation to -100 and set the blend mode to "color". On the layer below, adjust the hue back and forth, and watch the tones in the image change.