The easiest way to incluced "active" links in your posts is to "cut and paste", or more correctly "copy and paste", them from where ever. Though there are other methods, I normally copy the link from the "location" area in Netscape, IE calls the same area the "address". Needless to say, I hope, be sure you get all the address (some of them are quite long and extend beyond what's visible on your screen).
The above procedure has been complicated somewhat by Yahoo's attempts to reduce "spam". It appears that links are automatically detected by Yahoo's equipment which then (my knowledge gets fuzzy here) dumps the offensive post, or in some other way renders the post unusable. Not all locations are dumped though. What the critera is for "life" or "death" of a particular location I don't know. Some people have accused Yahoo of excluding links to sites they consider rivals.
Some spammers have started adding spaces in the address to disguise it from the system, allowing the post to go through. This method requires the reader to either retype the link without the spaces (A daunting task if it happens to be a very long one such as is common for a news feed link.), or "cutting and pasting" it into the location/address area then manually removing all the spaces, an imperfect solution at best.