How do I put a hyperlink in my Mail Signature?

Hi Everyone,
I would like to set up a signature for my Mail Version 3.6 (936) that includes a hyperlink and I am hoping that someone might be able to help me do this. I have already a basic signature going into Mail, then preferences then signatures.
I'd ideally like the hyperlink not to be seen but rather I'd like them to be able click on the words that take the reader to the target sight. in this instance click on the title of my book and the link automatically takes them to the sight. I hope this makes sense?
Please help!

Thankyou for your reply qCzar. Unfortunately when I do that it takes me to a box that only allows me to choose a link from my computer, not a URL. I think that may be the difference between the older Mail and the newer version.
Do you have any further suggestions that might help me link to a URL?

I think I've worked out how to do it.

It will only allow me to add a URL from a New Message. So, I have created and saved my signature as a Favourite Stationary, which I will have to select each time I write a new message. It seems tedious and if anyone can suggest anything more user friendly, I'm all ears, but for now, it works!