I am a regular reader of quite several websites or blogs related to Product Management. I would like to share the top 10 websites/blogs from them.

Website title: Silicon Valley Product Group (SVPG)
Intro: A website with lots of very good blog posts and articles about Product Management.
Website: http://www.svpg.com/
SVPG Blog: http://www.svpg.com/blog/blog.html
SVPG Articles: http://www.svpg.com/articles/articles.html
RSS Feed: (It seems that their feed has problems. It is better to subscribe their free newsletter via email on the website.)

Blog title: How To Be A Good Product Manager
Intro: Written by Jeff Lash, this sites provides regular tips on good product management practices. Every post is always structured as “If you want to be a bad product manager…” and “If you want to be a good product manager…”.
Website: http://www.goodproductmanager.com
RSS Feed: http://feeds.feedburner.com/GoodProductManager

Blog title: Ask A Good Product Manager
Intro: Put together by Jeff Lash, this sites provides real answers to your real product management questions. This site is an offshoot of How To Be A Good Product Manager.
Website: http://ask.goodproductmanager.com
RSS Feed: http://feeds.feedburner.com/AskAGoodProductManager

Blog title: PragmaticMarketing.com
Intro: Pragmatic Marketing provides training, consulting services and an online community for technology product management and marketing.
Website: http://www.pragmaticmarketing.com/blogs/productmarketing
RSS Feed: http://www.pragmaticmarketing.com/blogs/productmarketing/rss.xml

Blog title: Michael on High-Tech Product Management & Marketing
Intro: Although this website is not updated for a long time (most recent post was on December 17, 2006), Michael Shrivathsan published quite several excellent posts of Product Management and Product Marketing in the high-tech industry.
Website: http://michael.hightechproductmanagement.com
RSS Feed: http://feeds.feedburner.com/MichaelHighTechPM

Blog title: The Productologist
Intro: A blog by Ivan Chalif, who is Senior Product Manager at StrongMail Systems in Redwood City, CA. He has over 10 years experience in technology marketing, building web-based products and services at companies like ValueClick, The Gale Group and Acxiom Digital. Ivan is also a founding member of the Silicon Valley Product Management Association (SVPMA).
Website: http://www.theproductologist.com
RSS Feed: http://www.theproductologist.com/index.php/feed/

Blog title: All about Product Management
Intro: By Derek Morrison, this blog is designed to give tips on various aspects of the Product Manager’s and Product Development Manager’s role including interview and career suggestions.
Website: http://allaboutproductmanagement.blogspot.com/
RSS Feed: http://feeds.feedburner.com/AllAboutProductManagementByDerekMorrison

Blog title: On Product Management
Intro: Three professionals (Alan Armstrong, Ethan Henry, and Saeed Khan) co-author this blog.
Website: http://onproductmanagement.wordpress.com
RSS Feed: http://feeds.feedburner.com/OnProductManagement

Blog title: Product Beautiful
Intro: A blog about Product Management and Marketing created by Paul Young, who had worked in various Product Management and Marketing roles for Cisco’s Security and WAN managed services for several years.
Website: http://www.productbeautiful.com
RSS Feed: http://www.productbeautiful.com/feed/

Blog title: Product Management Tips
Intro: Gopal Shenoy is currently the Director of Product Management, Small Business at salary.com in Waltham, MA. Prior to salary.com, Gopal Shenoy has worked at RSA and also spend 11 years at SolidWorks Corporation, the leading manufacturer of 3D mechanical CAD software used by over 635,000 users in 80,000 companies.
Website: http://productmanagementtips.com
RSS Feed: http://productmanagementtips.com/feed/

Of course there are many other websites/blogs about Product Management and Marketing, such as 280 Group Blog, Forrester Product Management Blog, The Cranky Product Manager and many others. But generally speaking, the above ten websites/blogs are updated regularly and the article’s quality are generally very good.