1) thoughts on best method of converting to black and white (assuming
the in-camera option is a no-go)
There is no "best" anything in photography. There are probably a hundred different ways to convert from color to B&W. Some people have a personal favorite, other people have a few that they select from depending on the photo. John Beardsworth's book "Advanced Black & White Digital Photography" spends quite some time discussing the alternatives and their advantages and disadvantages.
In-camera is not necessarily a "no-go". As with any in-camera conversion, it significantly limits your options. If you happen to like what you get from the camera, then go ahead and use it. Shooting in-camera B&W is a different experience—a different gestalt—from shooting color and converting later. Some people enjoy the challenge, others don't. I happen to like it myself, and wrote a few notes about it here:
http://creativekarma.com/ee.php/weblog/comments/why_shoot_in_camera_bw_jpegs/
If you shoot Raw, there is no in-camera B&W. You can get a B&W preview on the LCD by selecting the Monochrome picture style, but the camera has a color sensor and so the Raw data contains full color information.
2) tips/advice/resources regarding different b/w styles. I'd like to
develop a better understanding of b/w styles- I know there are lots
of variety of b/w print films - what is the difference between Ilford
and TMax for example, and how best to replicate them.
The differences between films are not really applicable to digital. A film has a particular grain pattern. A film has a particular ISO. A film has a particular contrast curve. A film responds in particular ways to various developing solutions and processing techniques.
For the digital B&W photographer, your power tool is "Curves". This is what will do the most for controlling the "look" of your B&W photos.
Of decidedly secondary importance is color response. How much does the red channel affect the output, how much does the blue channel affect the output?
3) if it's worth using filters when taking an image, or is it best to
leave all this to post-processing
This is a somewhat controversial subject. You certainly don't
need color filters—any color filter can be simulated in post-processing. Some people feel, however, that a filter that cuts green can help by making the color channels more evenly balanced. In other words, you can increase the exposure to bring up the red and blue channels without blowing out the green channel.
Note: when shooting B&W film it was often recommended to use a yellow filter to "increase contrast" by providing a color response that was closer to the human eye's response. This is not necessary with your camera, even when using the in-camera B&W conversion. B&W film is over-sensitive to blue, while your camera's sensor is under-sensitive to blue. Using a "minus blue" filter on a DSLR is only going to starve your blue sensors.