Here are some to get you started. There are more on the way soon.
Torley Lives:
http://torley.com/
Archaeology:
Electric Archaeology: Digital SL Media for Learning:
http://electricarchaeologist.wordpress.com/category/second-life/
Business:
Metanomics- Business and Policy in Virtual Worlds.
Live weekly show featuring Robert Bloomfield from Cornell University's Johnson Graduate School of Management asking questions to the movers and shakers in business involved in virtual worlds.
http://metanomics.net/
Real Biz in SL - SLCN.TV show with Host Cybergrrl Oh who takes you on tour of real world businesses with an in-world presence as well as interviews.
http://slcn.tv/programs/real-biz-sl
Education in Second Life:
Problem Based Learning In-World - Meredith Snookums
http://pbl4sl.wordpress.com/
RezEd: The Hub For Learning and Virtual Worlds
RezEd (BETA), an online hub providing practitioners using virtual worlds with access to the highest quality resources and research in the field to establish a strong network of those using virtual worlds for learning.
http://www.rezed.org/
Best Practices in Education - SLCN.TV interviews major names in virtual worlds education.
http://slcn.tv/best-practices-in-education
English:
Literature Alive! in Second Life:
Started in 2006 it is an academic project in Second Life aimed at collecting and distributing resources for the development of literary projects of collegiate worth in SL.
http://collegeenglish.wikispaces.com/literaturealive
http://collegeenglish.wikispaces.com/secondlife
Government:
Confederation of Democratic Simulators:
Their wiki: http://secondlife.wikia.com/wiki/Confederation_of_Democratic_Simulators
or their or their blog: http://slcds.info/
History:
Coming soon...
Library:
ALA Marginalia: http://discuss.ala.org/marginalia/category/second-life/
The American Library Association is the oldest and largest library association in the world, with more than 65,000 members in SL.
Second Life Library Project: http://infoisland.org/
Whitehorn Library, Caledon Victoria City:
http://www.thelibrarymilitant.net/blog/
Museums:
The Tech Virtual Museum: http://thetechvirtual.org/
Want to create your own museum exhibit? Want to develop it with other creative thinkers and experts around the world? Want to share your exhibits with visitors in virtual and real galleries? This is the place to design and prototype exhibits online, using the web and Second Life. Start here to propose exhibit projects, share wild ideas and prototype exhibits.
Science
Chemistry:
Second Life consulting - Chemistry activities in Second Life
http://slusage.com/chemistry.asp
SciLand Virtual Continent:
The SciLands is a mini-continent and user community in the virtual world platform Second Life devoted exclusively to science and technology. There are over 20 science and technology related organizations in the SciLands, including government agencies, universities and museums.
http://www.scilands.org/
Metaverse News Outlets
Metaverse Messenger - The weekly paper of SL happening in PDF form.
http://www.metaversemessenger.com/
New World Notes - News Blog
http://nwn.blogs.com/
SLNN SL News When You Need IT, How You Need IT:
http://www.slnn.com/index.php
Reuters Second Life News Center:
http://secondlife.reuters.com/
Second Style: Web site for PDF magazine: http://www.secondstyle.com/
and their blog: http://blog.secondstyle.com/
Second Life Fashion magazine highlight user created content with a focus on haute couture.