Newsgroups, specifically NNTP, are forums in which people discuss given topics. Unlike blogs, which are people centric, NNTP feeds are subject or topic centric.
An example of a news server is msnews.microsoft.com. This publicly accessible NNTP site allows you to ask questions and give advice about various Microsoft products. Here's how:
Open the Account Settings window. To access newsgroups, go to the Account Wizard and click Add Account. Then select Newsgroup Account and click Next.
Provide your name (I recommend a nickname or just your first name because this name will be visible whenever you post to the NNTP group). Also provide an email address if you want. Most NNTP users obfuscate their email accounts, such as: thunderbird_userREMOVETHIS@hipsonREMOVETHISTOO.net; then they let the other party fix it if they want to send an email. Another trick is to use a disposable email account. This is important because posting in an NNTP group will almost certainly generate an enormous amount of spam email.
Many ISPs maintain NNTP servers for their customers. To use these, you might need a user ID and password. If necessary, your ISP will provide a password and basic instructions on how to configure the NNTP connection.
If the NNTP server you want to connect to requires a user ID and password, select Account Settings, click the newsgroup's Server Settings, and check the Always Request Authentication when Connecting to This Server option.
After clicking Next, specify the NNTP server's name. For the Microsoft groups, use msnews.microsoft.com. Click Next and, optionally, make the account name more user friendly; then click Finish.
After following these steps, you will have a new folder. Clicking the folder itself displays the Thunderbird manager window, and selecting Newsgroups, Manage Newsgroup Subscriptions enables you to subscribe to the various newsgroups available on that particular NNTP server.