It may not be obvious to those of you who haven't created a lot of online content how to create a hyperlink in your blog posts.  What you want to do is put in whatever text you want to use as your link, highlight it, and click the button on the toolbar that looks like a small chain link.  This will bring up a dialog box which will let you enter your url and info.  Note: the button will be greyed out until you highlight something.