The JDBC-ODBC bridge is just a reference implementation. It's missing a lot of functionality that is in the JDBC 2.0 specification. I couldn't get a metadata object using the bridge driver.
You should only use the JDBC-ODBC bridge to try out simple JDBC commands. Once you start doing some serious stuff with JDBC, then you should look into getting a driver implemented for your particular database engine.
Thomas' advice is a good one. Once you're comfortable or know that you'll be using a particular database, then get the JDBC drivers for that database engine.