Sam Bosma came to town, and what a neat guy he is, and he really loves to draw!
In case anybody missed his demo on how to separate linework to then color it, here goes!
Step 1, scan your drawing
Step 2, clean up your linework with the Level adjuster. This is easier when you're not using ballpoint or crosshatching, but it still works
Step 3, convert your image to grayscale mode (Image > Mode > Grayscale)
Step 4, now go to Channels, select the Gray Channel, then invert your selection (Shift+Alt+Command+I), copy, and paste. It will automatically paste your linework on a new Layer.
Step 5, make a new White Layer so you have your linework on one layer and your background on a different Layer
Step 6, on the linework layer, click the the little box next to lock, which will lock the transparency, so now you can only color inside the lines!
Step 7, convert back to RGB (Image > Mode > RGB, do not flatten when prompted) and have a color fiesta! And remember, you can even add a gradient to your linework layer, and it will only affect the line!
Wooo!!!!