Stage lighting

I'm looking for a tutorial or guide that can direct me through stage lighting.

I have managed to find the following link - http://www.renderplus.com/wp2/wk/Visible_Light_Paths.htm but this doesn't give me much information.

I am wanting to be able to show light beams from moving light fixtures, i'm also struggling with focusing the beam also.  I know to right click and select "aim lamp" but it really difficult to place it onto the surface I want.

I am using Irender NXT V: QF07nxt 7.0 and Google sketchup 2017.