Here is a list of the most popular and useful websites for IT Architecture, across a variety of topics and disciplines.
1. The core resource for IT architects https://www.opengroup.org/
2. Enterprise Architects Forum https://www.globalaea.org/forums/Default.aspx
3. TM Forum, essential and excellent for Telecom Architects and Designers https://www.tmforum.org/
4. The Zachmann Framework for Enterprise Architects is here. You can also certify in it. https://www.zachman.com/
5. OASIS – the organisation for open information standards and open-source https://www.oasis-open.org/