any suggestions?

As a matter of fact, yes :)

1. Visit PostgreSQL and take a look around.
2. If possible, acquire a copy of Practical PostgreSQL. Read it.
3. Check out some online tutorials, read some public discussions on the subject.
4. Start your project. After you've done that, finish it ;-).
5. Stand in awe of your newfound enlightenment.

Oh, and remember to use unique identifiers for the articles, it's more efficient and you don't risk having duplicates.