Hopefully everyone has visited the OpenNMS website several times to view the Community information there.
Check the About the OpenNMS FAQ regarding the OpenNMS project. The largest configuration is known to monitor over 28,000 nodes.
The OpenNMS weblog is one place to find recent community news.
For more information on OpenNMS Architecture check out this IBM DeveloperWorks article featuring OpenNMS.
Sparc users may want to deploy Debian using TFTP/RARP/OpenBoot to perform a network installation. The official Installing Debian on Sparc document has details on this process. Currently this type of installation will have to be performed from source as Sparc binaries do not yet exist.
The mailing lists at OpenNMS.org are the heart of learning and discussion for new and advanced users. If there are any questions regarding ONMS on Debian or any other operating system that are not easily answered in the documentation, post them here. This is also a great way to become an active member of the OpenNMS community.
O'Reilly's DocBook: The Definitive Guide
apache.org - home of Xerces, XML4J etc
Sun - home of JAVA
W3C Organization - home of XSLFO and XML
PostgreSQL - home of PostgreSQL
Blast Internet Services - Commercial Services for OpenNMS
Netstatz - Provider of Intelligent Linux Solutions, including solutions using OpenNMS with documents like this one.