Thanks to the growth of online degree programs and Web 2.0 tools, furthering your technical writing education has never been easier. Whether you're a current student looking for direction or a busy professional trying to squeeze in some extra learning, you can find technical writing courses or seminars that fit into your schedule.
The first place to search is the local chapter of the STC (Society for Technical Communication). Current members can offer a great deal of advice regarding programs they've attended, and many of them will be alumni of local programs. Most would be happy to converse via email about their experiences. Also, the local STC chapters will often host seminars and chapter meetings focused on particular technical writing topics.
You can also find class offerings online. Google indexes many pages from universities and other degree and certification programs. A thorough search should turn up quite a few training opportunities that meet your standards.
Last of all, don't forget to leverage the Internet's communities in your search for technical writing courses or seminars. Join the Techwr-l and HATT mailing lists, or other professional groups, and ask for advice from other group members. This is a great way to get feedback from your peers across the globe and expand your horizons. You'll also learn a lot just by watching the discussions that take place.