Let's see if this helps:
1. Old posts can be edited up to 24 hours, after that, you must post a reply to your post.
2. To add a link to a post, first copy the link you want to add to the post. Next, either click on the edit button (if you see it on your post) or the reply button. When the window opens with the text editor, you can do one of two things.
a. You can simply paste the link into the editor window (the place where you type your message) or3. Finally, to add a link to a new thread, just follow the directions in #2 in the new thread editor.
b. Write some text (like the name of your link: for example - say you want to link to your phal help thread, type 'My Phal Help Thread" in the window. Then highlight those words as if you were going to delete them, but instead with the words highlighted with your mouse, click this button on the editor and then paste in the URL of the link you want the words to link to here in the forum.
With all of these, click the preview post button to see if the link shows up. All links in the forum posted in threads open in another window, so click your link to test it. You should see the thread you want to link to in the new window.