How do I protect and market my code?

Basically I had a over the summer assignment which I used to develop a piece of software which I guess will sell around 50 - 70 bucks a copy.

To make this clear. The final code is in Java (a requirement).

Now I was think about marketing my little creation however I'm faced with two problem:

1, I need to provide full documentation to the Lecturers. How do I go about preventing them from stealing my code/methodologies used? Would simple copyright be enough?

2. How do I bundle the software? How do I sell it? Should I partner with a publisher or should I just sell the code to a software company? I will need bi-yearly maintenance at least.
How do I protect said software from getting cracked?

How /prog/ has some experience on this already!
Thanks for helping out!

>>24
Congrats OP a worker doing the most menial job you can think of made more than you did over the same period of time.
What if the guy goes to live in India?  I'm not up on how much the average over-seas rentacoder makes, but I bet $3.60 USD is an OK wage for a programmer over there.

In any case, I'm interested in what OP's product is actually for.  Even if he can't tell us exactly what it is.