Yes, if you have some SQL (the language, not SQL Server) knowledge it will surely help you.
The first thing I would recommend would be to <a href=”http://www.oracle.com/technetwork/database/express-edition/downloads/index.html”>download the express edition of Oracle Database 10g</a>, which is completely free. Then you can start learning from the <a href=”http://www.oracle.com/pls/xe102/homepage”>documentation library</a> which includes interesting courses such as “2 day DBA” and “2 day Developer Guide”, among others.
It is better that, if u have to do oracle certification i.e. OCP…. It has two parts one for Application Developer and other is Database Administrator (DBA). This is absolutely a global cert and u may get good jobs also. Other than there r so many certification in the same field like Sql Server or My Sql Server and so on. But must do a global certification. Rest just googling and u get all of the details !