Hi there, and welcome
How did I write a fan letter and send?
Your fan letter should ideally be one page long in length. No-one can tell you how to write because there is no perfect letter - just write about yourself, what you admire about the celeb, etc, and very importantly - that you are requesting an autograph.
Were did I get International Reply Coupon, and most I have them to send letter?
They should be available at your local post office. You don't
need them to send a letter because many celebrities around the world reply without IRC's/return postage, but it is better to include them. Especially when you're writing via venue.
How do I know if an autograph is real or not? And does it really matters?
There are tons of topics in the Collecting Help and Is My Autograph Authentic? forums that can help you out with this. You're always welcome to ask a member of the board what they think when you receive feedback - you'll learn quickly how a stamp/autopen/preprint and so forth looks.
Sometime I get a CoA can I trust that?
These mean absolutely nothing, because people are horribly untrustworthy, and can print these certificates themselves. Even lots of third party authenticators are corrupt, check out
http://www.autographalert.com for more on that.
TTM
= Through The Mail - all autographs received by post.
AP
= Autopen. A machine that holds a pen and is programmed to sign like a certain celebrity. In other words, a fake autograph.
PP
= Preprint. Another fake autograph - it's basically a photocopy of a signature, the signature is part of the photo.
IP
= In Person. An autograph obtained in person, for example, if you had to meet a celebrity outside a hotel.
Any other questions feel free to ask ;)