> Somebody has documentation on the connection to Firebir from Java? I
> appreciate any collaboration.

You need Jaybird JDBC driver (available from SourceForge download). It
is standard JDBC driver, so whatever documentation you have would be ok.
Also the sources contain an example of obtaining the connection

The configuration topics are documented here:

http://jaybirdwiki.firebirdsql.org/jaybird/doku.php?id=config:start

Roman