[tmac58star]

Set the deck/cut height with the knob, then set the wheel height...the wheels are just an anti-scalping feature...deck should hang/float freely from the tractor frame.

 

[tmac58star]

Now my 330 has the same looking deck but that has hydraulic up and down. For that deck i set the 4 wheels to a 4in cut and then lower it down so it rides on the ground. There is no knob on that tractor to set the deck height. This 212 i have having the same deck as the 330 and the same sticker on the deck shows how to set the deck for a certain cut height how would i know what height the deck is via the knob. Do i just turn the knob and guess at what height feels good on the lawn?

Yeah set the wheels slightly lower than the deck, which hangs freely from the frame...anti-scalp measure.
The depth STOP set by the knob on these tractors sets the lowest point you want for the deck...typically your mowing/cut height.
Get the deck level with wheels up, side to side by adjusting one of the deck hanger straps...the other isn't adjustable. Put it on a level smooth slab and check height of the blade tips/edges front to rear and side to side. I set all mine at 3.5 inches.
You're also supposed to have the nose/front of the deck slightly lower than the rear.
Raise the deck up, turn the STOP knob in or out to get the cut height you want...takes a while to find this knob setting. Lower the deck, check blade tip/edge height...and adjust until you get the height you want. Raise the deck fully between each adjustment, drop it to check/recheck blade height.
I mark my fender pan with 2 pieces of white duct tape, one on fender deck, one on knob. When aligned the height is right.
Then drop the wheels slightly below the edge of the deck...now they hang like the deck, but keep the deck/blades out of the dirt/rocks, etc.
After a while you can raise/lower the depth STOP pretty accurately from the seat. Meanwhile you get a good arm workout with the deck lift lever! Unless you have a hydro tractor with power lift.
On your 330 use the big threaded rod on the rockshaft to adjust the depth STOP...like Drafter says.