Dave;
The boat retailers have shelves of products to choose from because there are so many opinions and you will hear a few on this forum. Having had a Ranger 25 for 7 years and currently have a Ranger 29, I can only speak on what works for me:
Use Dawn soap if you want to strip off the wax, otherwise use a carwash type soap. Use the product FSR (fiberglass stain remover) if there is light oxidation of the fiberglass. This is a very mild, mild acid that when rinsed brings back the shine. wipe it on, let dry and rinse off. For medium to heavy oxidation, use a rubbing compound (I use the Starbrite product line). Then, wax it.
I really like the liquid wax products that have teflon in it. Smear it on, let dry, wipe and you are done. Do it again within 30 days and the tug will look fabulous for an entire season. However, I do not use this product on the deck surfaces because it is too slick.
Once the wax coats are on, the tug is cleaned with a spray bottle of 50-50 vinegar and water. This clean really, really well without taking off the wax. No Salt-Away, no other cleaner. Wow and Andiamo looks great.