Reddit reviews Mastering Digital Black and White: A Photographer's Guide to High Quality Black-and-White Imaging and Printing (Digital Process and Print)

The definitive book on the subject is Mastering Digital Black and White by Amadou Diallo, although I did not find it particularly useful :)

By far the best thing you can do is purchase Silver Efex Pro (SFX).

Since you're used to the zone system you'll feel right at home in it. It even has a zone system histogram where you can highlight which areas of your photo fall into which zone. The individually adjustable highlight, midtone, and shadow settings for things like brightness, contrast, clarity, etc. are invaluable when you are used to thinking in terms of tones. The control points are a fantastic, fast, way to do local adjustments. They are much easier than little pieces of cardboard and your hand in the darkroom :)

You can use Lightroom or Photoshop to achieve similar results, but personally I find them immensely frustrating for B&W work and always, always, always, use SFX.

There are people who say that SFX is nothing more than a bunch of presets, but they haven't dug into the program. Yes, there presets you can apply to get started, but that's no different than presets in Lightroom. They're just starting points for your vision, which you then refine through tools dedicated to and designed for B&W.

All of the B&W images in my Southwest 2013 gallery were converted using SFX. Mesa Clouds, in particular, was one that took two weekends of work to convert using SFX to get what I wanted from the terrible, terrible, original. More examples can be found in my Washington Coast gallery. All the B&W/toned images from the Hoh Rainforest on were done with SFX, including the selectively-toned trees, which was all done using SFX control points.

One tip: Don't use SFX with Lightroom. Instead open your image in Photoshop and use SFX as a Smart Layer. That way you can go back and do infinite non-destructive re-edits of your B&W conversion.