Type your post, including the title (such as "here") that you want to appear as a link.
Example: "Pictures are posted here."
Then highlight the title by positioning the mouse in front of the first letter, and dragging it to the last letter. (Forum code doesn't have a way to show this, but there will be a dark blue background for the letters you have highlighted.)
Now click on the icon of a globe and chain. That's the one that pops up "Insert Link" when you hover your mouse over it.
A popup box will appear. Type or paste your url in the popup box and click "OK".
Example: Highlight the last three words in this sentence, and go from there: "Here is a picture of what is said to be the world's largest coin."
There you go. Click on the link and feast your eyes.