CTRL + LCLICK adds/removes selection
CTRL + LDRAG box adds to selection
ALT + LDRAG box removes from selection
SHIFT + LCLICK on a vertex in a 2D view will not select vertices on top of eachother (closest one gets picked), otherwise all are selected.
In brush face mode in the 3D view: CTRL + LDRAG scales texture, ALT + LDRAG rotates texture, SHIFT + LDRAG shifts y tex, LDRAG shifts x tex (move mouse up/down).
Cannot delete verts on brushes explicitly, but you can collapse them and they will be removed.
Press W while mousing over a view to toggle minimized and maximized.