any and all suggestions/insight into quickest mode of public transportation from within 30 miles of Vernon, NY into Manhattan

Vernon or Mt Vernon? Big difference.
Mt Vernon, take the train. New Haven line of MTA, Metro North

How quick is quick? You're going have to travel at least 6 hours by any method (not including the time to get to your starting point from Vernon).

The nearest rail stations are Amtrak's Utica, NY or Rome, NY stations.

Amtrak's Empire Service operates a number of trains daily and it takes about 6 to 6 1/2 hours to get to NY Penn Station.

http://www.amtrak.com/home
- on the Amtrak page put either ROM (for Rome) or UCA (for Utica) in the 'from' box and NYP (for NY Penn) in the 'to' box. Select one-way or round trip, change the date as needed and leave the time as "Anytime" so you will get all the trains for that day. Then click on GO and you will get the trains and fares for the day you selected. You can make reservations (usually required) from that page as well.

You can also check with Adirondack Trailways Bus to see what service they have from Rome, NY to NYC (Port Authority Bus Terminal):
http://www.trailwaysny.com/

From VERNON? There is train service from Utica, operated by Amtrak, into Penn Station.

I must admit I have never heard of Vernon. If you live there wouldn't you know the best way to get to Manhattan? And if you don't live there - it seems an odd place to be traveling to.

There don't seem to be any buses from Rome but quite a few from Utica - the fastest being a 7:45 am bus that takes about 5 hours to Manhattan.

Certainly not a round trip for one day

There is Vernon, New Jersey and tiny town in upstate NY.

My bad, I misunderstood the information my friend conveyed to me - it is in fact Vernon Township, New Jersey!...sorry about miscommunication = any further suggestions would be much appreciated, thanks

Well the details will depend on exactly where you are. NJ transit has a number of trains and buses into the city from there - but you will need to get an exact location so you know what is most convenient.

Check the specific town and then go to the NJ transit website and chose either train (faster - maybe an hour)or bus (perhaps 1.5 hours but may be a closer location)or both and search for your options. Without knowing a specific town can;t give more advice.

Far northern New Jersey is not served well by NJ Transit trains, and I am not very familiar with that area, but my guess is that you would have to take a bus ... probably from West Milford. And that must be a 90-minute or 2-hour ride. And it's likely there is really bad (or nonexistent) service on the weekends.