Open up the blog page you want in your browser.
Use your mouse to highlight the text in the location bar. That''s the text that begins with http://
Pull down the Edit menu of your browser and choose copy. If you are using Windows, you could also use Cntl-C and on Mac, Command-C
Then go to your hub. Click edit in the capsule where you want to link. Select the specific text you want to for the link and then click the icon that looks like a chain. A box pops up. Click in the top field of that box and then select Edit -> Paste from your browser or Control V for Windows, Command V for Mac.
Click OK. You have a link.