Welcome to Card Creation Studios !
If you don't know how to create acard,not abig problem you'll find the solution as you continue reading

First,You Shall find aplace where you can get images,pictures...etc from like photobucket,tinypic,google

https://www.photobucket.com
http://www.tinypic.com
http://www.google.com

Second,There's a PC software called Yugioh Card Maker which you can search for it at google.com or you can go to the following link to create an online card

http://www.yugiohcardmaker.net/

Third,Upload your card either on photobucket,tinypic,imageshack

Post the image link
That's It :D

As for the way of posting. Each Member will create his own profile and post all his works in there