Is there an easy to use (no programming required) software/app for using an API with Intersango, CampBX, Mt.Gox, etc? Or, can someone explain how to use an API to manage trades as simply as possible?
(please advise if this question has already been answered somewhere else.)
Not really, if you want to use an API, its assumed that you will know some sort of programming language. Get learning.
Some people might be kind enough to send you some pre-written classes however you'd still need to understand the language to use them.