PL/SQL practice questions site needed!!!

Where can I find free site where I can download or practice Pl/SQL questions?
Is there any site which allow Pl/Sql script to run and test on line, or is there any light editor where I can test my Pl/sql script.

Why can't you test your scripts in a database you create?

http://www.bookpool.com/.x/tpc8wzknni/sm/0130473200

http://www.bookpool.com/.x/tpc8wzknni/sm/0131172611

http://www.bookpool.com/.x/tpc8wzknni/sm/0596001800

Any specific reason to do it all online?

Start with this book...http://download-west.oracle.com/docs...a96624/toc.htm

and more examples...

http://otn.oracle.com/pls/db92/db92....category=plsql