Hi,

You know the stuff and are on the right track. My suggestion would be to take up some development job which gives you good working knowledge with sql', the entire working environment, different practical concepts.
On the go, you will come across different problems you try to solve them yourself or work with your DBA's to see how they do it.

There are ton's of documentation available on otn.oracle.com or metalink.oracle.com websites.

About the
"job of a DBA", It's ones comfort level with tackling the jobs. Initially you find it stress full but it's not so (sometimes depends on the nature of your business).

About the roles of dba, check this forum and you will see on many occasions this topic was discussed

Badrinath