Use social networks like Facebook, MySpace or LinkedIn and build relationships with people working in the music industry. Several producers also maintain their own accounts and can therefore be reached directly on those sites.
Go to music-related events, such as conferences, concerts, or televisions shows which feature live music performances, and attempt to strike-up a conversation with a music producer, or one of his assistants. Don't be pushy, but don't let the opportunity pass by.
Send your demo tape or lyrics directly to the record company, using the link found on its website. Record producers are always looking for fresh new faces and innovative talent. While it may take a while to get a reply, sending an email is a free opportunity for you to get your work noticed.
Read music-related magazines and newspapers, in order to keep up to date with what is happening at the moment in the music industry. You will also learn the names of the major producers, and you might get some useful information about them, such as the name of their favorite club or restaurant, allowing you to easily set up a meeting.