The best place to start for simple databases is are the tutorials here:
viewforum.php?f=13
These cover using the database actions but if you are looking to develop more complex databases then I'd stick with scripting as it offers greater control.
Be aware that depending on how complex your quiz, will influence the amount of work required for saving and restoring a session to it's previous state. What might seem simple can be a lot of work to achieve this.
E.G A quiz that simply has text inputs can simply read / write variables to the database but a quiz that uses lookups, drag and drops or other complex answer systems will require that these set once the data as been read from the database.
With this type of project, we always plan on paper what sort of questions are used, the data that would need to be stored and how we would use that data to recreate a users initial answer before starting.
Mack.