The 'easy' version:
place your URL between [ url] and [ / url] (without whitespaces).
The more complex version that does display not the link but an alternative text:
[ url =
http://the-url-you-want-to-link.com]Text that shall be displayed[ / url] (also without whitespaces)
ah, yes, or just paste the URL, most times the forum automatically will display it as a link :)
hmmm... was that really your question? ;D
What do you mean by "embed"? ^^