It took me a long time to get it right.
Click on the URL above [url]
Then you insert = between the l and the ] [url]
When your curser is after the =, paste your link [url=http:whatever]
immediately after the second ] type the word you want [url=http:whatever]here
Then click on the URL again (it will have an * )
When you have a real link it will look like this