Without knowing your work experience, or your long term goals, I really can't give you a specific class to take, but I can give some places to look.
If I were you, the first thing I would do would be to attend COMMON. COMMON covers a variety of topics which are presented by IBM and industry experts. The next COMMON conference is coming soon May13-17 in New Orleans. This will help you decide which topics you want to further explore.
There are a multitude of specialty seminars targeted at a variety of AS/400 topics and professionals. Having attended several of these, I can tell you that the cost and quality of these vary greatly.etnetworks.com delivers multimedia training directly to your office thru a combination of satellite and the Internet. They appear to offer an excellent range and depth of subjects as well as being reasonably priced.
This was first published in March 2001