ZBrush questions

I have been doing sculpts like this recently using blender to model and zbrush to sculpt in details http://www.artbydavidvessup.com/images/sheet_brokenColumn.jpg
My issue is I only know reaally basic zbrush. The only things I know are loading in my model, clicking the edit button to do 3d and using a few default brushes. Just knowing this is enough to do a lot of sculpting but I want to learn more. I saw someone at my school using a feature where they clicked a button and it would change stretched topology so that it had as many verts as everywhere else and I want to know more about that.
And I was wondering what sort of brushes might be helpful for doing sculpting of broken stones like in that photo. I have just been using the fracture brush and the standard brush. I can get the results I want but it can be very tricky and I assume there is a brush set somewhere for making it easier. Also I was wondering what the hotkey is for subdividing in zbrush and where the “lazy mouse” feature is.
Thanks in advance for any help!

I saw someone at my school using a feature where they clicked a button and it would change stretched topology so that it had as many verts as everywhere else and I want to know more about that.
Dynamesh. enable in the Tools / geometry palette. Look on the pixologic website for tutorials about using dynamesh. There are also details in the manual that is in your zbrush document installation directory.

Subdivide if I recall correctly is Ctrl+D (read the tooltip for the subdivide button, it should tell you), for lazymouse I believe look in the stroke palette

Lazy mouse is also the L hotkey, unless I changed that myself

For the stone, there’s a brush called “mallet fast” that is included with zbrush. It’s not active by default, but you can find it in the lightbox under brushes > mallet. It’s really useful for flattening and chipping corners. The crumple brush can also be nice to mess up an area you’ve already chipped/grooved a bit, gives it more of a natural “fractal” look.

Also, see this thread: http://www.polycount.com/forum/showthread.php?t=92406

Thanks guys! All very helpful!