In short I completed following steps of my AZ-EQ6 mount :
1) setting the mount stable and balanced using the bubble of the mount
2) setting the home position - both RA and Dec
3) alignment of the polarstar within the polarscope
4) 3-star alignment using the Synscan of the mount
Visible "goto" observation showed good results with the object in field of focus. Tracking was set and ready to make my first pictures with "long" exposures up to 30s.
Personally I'm very happy about the result of both M57 and M13.