Where can I find any information regarding extra pay or daily work schedule/life while on a ship?

Probably be on a RORO.

I traveled from Saudi Arabia back to Germany as a "super cargo". On the first day we went through all of the cargo decks and picked up any left over trash and rechecked all tie downs. Then, if I remember correctly, a couple of days before we hit port we started all of the vehicles that could be started. They had large fans going in the holds to vent the fumes. The only other thing we had to do was behave ourselves, let the crew sleep, and don't interfere in the crew's work. You'll be briefed by one of the ship's officers after you cast off, or before it. I got per-diem(sp) pay while I was on the ship. It's going to be a bit boring at times, but I still value the experience from it.

unless that boat goes under water, you probably won't get extra pay.