Break it up into pieces.
- You can write one module that controls access to the database. This should have add, delete, update, and list methods.
- The quotes themselves could be objects with methods to provide the quote itself, its author, etc.
- The web interface could be modularized depending on how you intend to implement it and what webserver and application framework you're working with.
Doing the database as a module allows you to easily substitute another implementation that saves to text files, a different database, db files, or whatever.
Doing the quotes as an object allows you to write a command line utility that accesses the quotes.