Any%
Any% is the fastest way to finish the game. Finishing refers to beating Bowser for the last time in the story line (which is in Moon Kingdom).
Route
The route in Any% is mostly modular. Meaning, each kingdom has it's own route that doesn't impact any major aspect of the route in another kingdom (with the exception of the coin routing which is a minor aspect)
The complete route document can be found here.
Tutorials
Smallant1 made a great series of tutorials oriented towards beginners. This is a definite must watch for anyone looking into running the game.
https://www.youtube.com/playlist?list=PLiinoyifvFb64od8RyqPFmVqDrFwkgaa0