I see you use .jpg images. Will I be able to use .gif?
I have never used a .gif, but the imap.map script isn't dependent on any particular kind of image file. The image only gives that script a way to be used, so .gifs and most other image types are usable.

Am I restricted to how many links I have?
You are only restricted according to how much space you use and the limitations of the size of the image for signatures.

Is there anything special I have to do to make it work?
As long as you follow the guide, it will work. You will need a hosting site for the imap.map file.

My image isnt working. Is my coding right?
If you followed the guide you did. Chances are your issue is that you are using img inside the [-] rather then imgmap. Try using imgmap.