Hot off the Press: Outboard Maintenance Recommendations Manual. Part# 8M0186321.
This manual can be special ordered through Rhonda, or any Authorized Mercury Dealer. It is available in ONLY Paper-Manual format.
Covers all Current (and Recent) 4-Stroke Models, as well as the 3L Optimax models (including ProXS).
Covers engine Specs, Recommended Maintenance, and has detailed procedures for a number of the common items you would be doing during that maintenance.
Though written for Service Techs with a solid understanding of the engine and it's systems, I believe it would be an invaluable tool for a Do-It-Yourselfer as well.
I like just because it's got the info for any current productions model right there at your fingertips!