Hi Mike, Welcome to GG Riders Club.
Boys you've got a loaded question there which has been discuss since this place started.
Rule of thumb is Good quality, lower first number (like 0w40, 5w40 to prevent clutch drag) and change it lots.
If you use the search button up top and search just oil you'll be back reading a long time.
But for now here are a couple newer threads that will interest you.
Hope that helps ya out a bit.
Oh and Congrats on your new ride.
ec 300 transmission oil
Oil types/best?