It’s easy to forget the subset standards of the PDF, especially with the recent ISO certification of the PDF 1.7 specification.
You don’t usually hear about these subset standards unless you actually use them. Likewise, you probably don’t see many resources on the subset standards unless you actually look for them. Fortunately, there’s the PDF/A Competence Center (how could I have missed this site?).

In case you’ve never come across the site, the PDF/A Competence Center is an association of tech companies and PDF experts primarily focused upon promoting the exchange and use of PDF-based archives.
If you’re looking for PDF/A basics, FAQs, press releases and technical documentation, the www.pdfa.org website has informative articles and resources for both PDF/A creation and usage. The site is continually updated with specialized forum discussions and news.
In fact, they’ve been advertising the first ever 2-day international PDF/A conference from April 10th-11thin Amsterdam. Much like the Adobe PDF and Acrobat Conference, it’ll cover different types of tracks on popular PDF/A topics.
Day One will hold separate knowledge tracks for beginner, intermediate and advanced user levels covering topics such as digital signatures, application scenarios, document scanning, fonts, text and Unicode, PDF/A-2 and the legal implications of using PDF/A.
The industry tracks on Day Two will take a look at the role of PDF/A and best practices to follow in the libraries and public sectors; engineering and manufacturing; and business to customer industries.
You can register online for the event. Or you can get a copy of the flyer here—which you can fill out and submit online.