Any manual is better than none. I have the Clymer and Honda manuals. The Honda manual is better IMO.
As Soaked Karma says, you need to remove the rings from the Piston and fit them into the cylinder bore in the unworn section near the bottom to check ring wear by measuring the end gap with a feeler gage. Make sure it is perfectly square with the cylinder. be careful not to break the rings or scratch the piston when removing and reinstalling them.
The maximum gaps allowed are .018, .024, .035 inches for the 3 rings from top to bottom.
2004 Rebel 250, 2003 BMW K1200GT (roadburner), 2004 BMW R1200GS(all purpose),
1996 Ducati 900SS CR (California Bike), 1973 Norton Interstate (in a box in the basement)