Welcome, jeena1. (Edit: Spam links have been removed. Time to find out if this was a real post! Ready? Set? Go!)
If it isn't Spam, then:
Everything Yagyu said.
In addition, many people (Penny Arcade
comes to mind, for example) use graphical software such as Photoshop (or it's free counterpart, GIMP 2
) in combination with a tablet, such as the kind WACOM
makes (this is what I use).
There are various other retail, free, and open source imaging programs out there - Inkscape
is another example. Spend some time with Google if the examples in this thread don't work for you, and you'll eventually stumble upon something you like.