Ciatta.. no problem!!!
When you are posting a reply you will see some tabs above the writing box (starts with the A, Bold, Italics, Underline, Color...) The world with the "link" chain is the next tab (between the color option and the picture of the mountain). This is what you will use to type the link into!
Now if you want to say something like "Go here for link" and you would like that to be underlined and be a direct link- you Highlight the text that you want to be direct linked and then click on the world with the link chain and add the link.
Does that make sense?
Try on here on this thread and let me know if it works out ok for you!!