News Flash! Outlook does not have a news reader.
If you really want newsgroups in Outlook, there are add-ins below which will add an NNTP transport to Outlook. These are best used with a small number of newsgroups or news servers as they can negatively effect Outlook performance. You should use a Unicode PST with these add-ins, so that you don't have problems with data loss due to an oversized PST.
My preference? Outlook for e-mail, a News reader for news groups. They both offer much better View capability - such as showing only threads I'm posting in and marking my posts and replies to my posts as watched, so I can find them easier.
Newsgroups in Outlook (Outlook-tips.net)