One of my schematics says I need a ruby ring but I have no idea how to acquire one or build one. Is there a place on the site that lists out what is obtainable from an island and what you have to build? Would love to know. Thanks for the help!

A ruby ring is an item you have to craft. You can find the list of items you have to build under Help > List of Recipies. ^^

And there is a nice guide of items found in explore here:
http://beastkeeper.com/thread/8104