If you are using Outlook 2003/xp/2000 or Outlook Express, you want to read rss feeds from your outlook/outlook express you have to use addon called RSS Popper.If you are using outook 2007 there is already built in feature to read rss feeds.
First you need to download RSS Popper from here
Features (Partial list)
* Supports MS-Outlook 2000, XP, 2003, 2007 (RSS Popper)
* Outlook Express 6 (RSS Popper for Outlook Express)
* Supports all RSS, Atom & RDF versions
* Support Podcasts
* Bloglines.com synchronization
* NewsGator Online synchronization
* Enable full page download to Outlook (i.e. Off-lin
* OPML Import/Export
* And much more…
After installation RSS feeds are displayed under a folder called RSS in the “All Mail Folders” pane on the left-side navigation. The keyboard shortcuts are to hit “Ctrl-Y” to bring up the Go To Folder menu, then hit “R” for RSS and enter.
You can also use Newgatorinbox