This may sound like a trivial request, but I was wondering how I'd go
about converting a color line drawing (like a cartoon) that is in a
TIF format and has a white background... to a B/W GIF with a
transparent background.

When I use the magic wand method and fill in all the colors with
black, I still get a very pixelized edge on the cartoon lines. I even
tried changing the mode to grayscale... didn't help.

I'm probably in the forest and can't see the proverbial trees. Tell
me it's a simple process. My original image is in 300 dpi resolution
if that helps?

Mike