[eluser]Majd Taby[/eluser]
There are three bundled plugins of interest: DbDropDown, ManyToMany, and OneToMany. Look at the bundled example for a template on how to use them.
DbDropDown populates a dropdown with the contents of the other table
ManyToMany sets up a many-to-many relationship between two tables (where many fields in this table can be paired with many fields from the other table)
OneToMany sets up a one-to-many relationship between the two tables (where each field may relate to many fields in the other table, but each record in the other table can be paired with only one record in this table)
You can google the relationships to see how they work.
