There are several great architectural resources out their on the web that may not be 'common knowledge' to those in the field (and those out of the field for that matter):
Architecture Week - Great articles about current projects, job search, directory of architects, competitions, and much else related to architecture.
The Architectural Review - by far the best architecture magazine in print (though rather pricey and uncommon in the US); online usually there are just a few articles that are published, but it gives great building reviews and there is an index to all the magazines for each 6 mo. period to look-up buildings, articles, cities, materials, etc.
Los Angeles Forum on for Architecture and Urban Design - look up competitions, read articles, check out publications. It's not all about LA - the ideas behind many of these articles are a great reference.
Architecture for Humanity - This is a non profit organization that takes on projects primarily related to disaster- relief and sustainability. If you are looking for ways to volunteer your time or yourself, they provide ample opportunities within the US, and some outstanding opportunities abroad to help foreign communities develop or recover.
Open Architecture Network - This project stemmed from Architecture for Humanity. It is "an online, open source community dedicated to improving living conditions through innovative and sustainable design." There is a library of projects that discuss keep track of the process of projects and design/ construction/ budget solutions.
Death by Architecture - This website started out by posting architectural competitions and has been the best one out there since. It is a great resource for finding an architecture competition (it organizes in a calendar format based on deadlines). And there are several good design related articles also posted.
European Urban Knowledge Network - On this website, you will find the e-library section that has several publications, articles, and studies related to urban issues. The publications are book-worthy and you can read them here for free.
Archinect - This is another great catch-all website. They list competitions, book reviews, building reviews, jobs, forums, and archmart.
(Article to updated as more websites are discovered.)