You'll find the Feeds tool in the right-hand sidebar of Lotus Notes.
If you don't see Feeds there, try the drop-down menu from the upper-right corner of your Sametime Contacts list.
From that drop-down menu, select Sidebar Panels and then, on the fly-out menu, make sure Feeds has a checkmark next to it.
To add a feed, look for the RSS icon on the website. Right click over the link and select Copy Link Location on the right-click menu.
Back in Lotus Notes, click the Subscribe to Feed icon in the Feeds tool.
And paste the link into the dialog box that opens. Click Go. You can change the settings if you want or just click OK.
The feed will appear in your Feeds list. When you expand the heading, it will show articles and posts underneath, where new unread items will be in bold.
Clicking once on an item will display a preview window. Double-clicking will open it in the Lotus Notes browser.