Prepress Seminars/Conventions/Expos: What's worth my time?

Hi All,

I'm new to prepress and the printing industry in general. I have a working knowledge of what's going on but am always interested in finding avenues to learn more. What are your thoughts and/or experiences on specific printing seminars/conventions/expos? Are there certain ones that are geared toward prepress? Which ones should I stay away from and which ones are worth my time?

Thank you!