I’d say study a lot. The hot keys for these functions (modes) are:
q = draw
w = move
e = scale
r = rotate
These options are also in the top tool bar, above the canvas, in the ui.
What you don’t have masked will be affected, down to the polygon. There are a few ways of masking and adjusting the masked areas. The softer the mask, the smoother the transition along the border of the masked area.
Study masking and transpose a lot. Don’t post too many questions before studying up. Pretty much everything you need to know is out there. I feel you, though, because I’ve been there on many occasions, not just with ZBrush. I know that “WTF” moment, believe me, and it’s not like 3d is simple. Here’s the ZBrush wiki:
http://www.zbrush.info/docs/index.php/TOC
…and the zclassroom link:
http://www.pixologic.com/zclassroom/
While your at it, download the subtool master and transpose master, if you haven’t already. These are two very necessary plug ins that affect the posing capabilities of ZBrush.
http://www.zbrushcentral.com/zbc/showthread.php?t=057154 (subtool master)
http://www.zbrushcentral.com/zbc/showthread.php?t=54270&highlight=transpose+master (transpose master)
Good luck!