I want to be able to track changes that are made to a
particular field. Also, I would like a time & date stamp
indicating when the change was made.  

For example, a contact name changes. I want to see the old
names and when each time that field was changed.

That will be a lot of effort to implement across an entire
database.  If it's just one form and one field look into
linking it to an event: beforeupdate or changed depending
on what's going on in your design.