Hello guys, newbie question here. How do you trigger a user event when a record has been updated(Edit > Save)?

NetSuite is triggering the user events automatically (unless it's being trigger ed from other user event). So if you are referring to UI edit&save, there is nothing you have to do...

sorry, what I meant was how do I run a client script triggered from a user event script when there is an update on the record(let's say a field is updated).