putting signatures in emails

[Jane Jordan (Gmail)]

I *think* there is a way to put signatues in emails, but I have never  
tried it.  What I want to know is, Can I have a different signature  
for each email adress/  I have three, so I might want there different  
ones.

If so, how do I set them up?  I have never played aorund with this  
signature thing, but I figure it might make some of y emails look a  
little more professional.  This came to mind because while I was at  
work today, I noticed a couple of my older coworkers get all excited  
because they figured out how to put signatures into their emails, and  
they were going on about how it would save them lots of typing.  They  
have long titles, and a phone number--two of them, and an extension.   
So I was beginning to think about it for me and wonder if it is  
possible to have sepate ones for each email adress.

Thanks,

Jane