Very good advice and I'll add a suggestion to start a sketch of all the components you find in their approximate location for future reference. Many of the MS supplied schematic / arrangement drawings are incorrect - not a bad place to start but trying to locate and confirm each system / component - especially those with thru hulls/seacocks is a very worthwhile exercise.While you are waiting for a Mainship owner to respond, I would strongly suggest you start opening up all your bilge hatches to see what you've got down there.
Crawling around the bilge exploring is a great way to learn your boat. I would bet that 90% of the owners here have a pair of knee pads on their boat.