Larry, I agree with the others about Calder, but..
a manual for your particular diesel is useful too. It will have pix and explanations that relate directly to the make and model of the engine on your boat. I ordered manuals for the engine (Westerbeke 2-10) and transmission (Hurth-don't remember the model no.) on my boat, and have found them both to be useful. You can order manuals from a Universal (Westerbeke) dealer. Try Torresen Marine Diesel Direct on the net. Last year they were participants in a Guest Forum here on the site, and gave out some super info on diesel maint. and repair. Web address is www.marinedieseldirect.com.Tom