3D coordinate system with Z=Up - rotation directions and starting axis ?

Hello all,

I've used OpenGL to create a basic 3D coordinate system (which works) with 
Z=Up, X=to the right and Y=into the screen.

The thing is that I've picked rotation directions and starting axis for 
those rotations in a "I need it to work, and this does" way. :-|

Now I'm at a point where I want to make it conform to a/the standard, and 
have done a few websearches for 3D coodinate systems and their specifics.

Alas, although I've been able to find pictures of the Y=Up and Z=Up 
coordinate systems and even a Z=up, rotation=anti-clockwise description 
(right-hand rule), I could not find anything more - which suprises me to be 
honest. :-|



What I'm looking for, for both the Y=up and Z=Up coordinate systems :

rotation directions for all three axis/planes, as well as starting axis*.

* Although I've found that for Z=Up the rotation direction is 
counter-clockwise I do not know at with axis it starts: +X ?  +Y ? 
 Perhaps -X or -Y ?.  No idea. :-(

Regards,
Rudy Wieser