You also have to be careful about reverse engineering code in the sense that if you base your "new" program on existing code that is proprietary, and it can be shown that what you write is derived from that source, it's all kinds of copyright problems.
The open source world is a lot friendlier in that sense -- licensing allows you to see and work with the code as long as you follow the guidelines of the code creator's license.
Poke around, Squall, and you'll find something in your level of knowledge...never hurts to ask, does it?