It can tell you the year of the tractor and if you want to find out all you can, have it researched at http://www.twocylinder.com/research.htm
Your John Deere 322, serial number M00322x596318 is a 1989 model year.
2004
1983 Model Year
1999
I think this is a model X475 made in 2004
1966
4,000
1995 model
Write down the serial number and take it to your John Deere dealer.
Your John Deer is a 1992 per John Deere serial number list provided by manufacture.
A John Deere model M tractor serial number plate is riveted onto the engine block on the left side of the tractor.
This was made in 1949. John Deere "MT" Beginning Serial Numbers: 1949- 10001 1950- 14728 1951- 26203 1952- 32813