Q: What code should I write to start with? A: Something that sounds interesting.

Sounding interesting shouldn't be the only requirement. An understanding of the problem space or the ability to gain that understanding quickly should also be a prerequisite. And, since we are talking about Perl, Perl should be an appropriate language to use to solve the problem.

Q: Should I write one-liners? A: No, write real-world code. One liners are for people who don't know what the word "maintenance" means. Write real-world, reusable code.

There is nothing wrong with writing one-liners when they are called for. There are plenty of one-time tasks that can easily be solved in one line. Trying to get a one-liner right can sometimes be educational too. Anything that increases your familiarity with Perl might be considered a good thing. Just don't always resort to a one-liner. If you are going to have to do the same task tomorrow or next week, write script and improve it over time.

Q: What license should I release my code under? A: The GPL. It is solid, relatively tested, and will ensure your code remains free.

It continues to be tested and that indicates that its solidity isn't a foregone conclusion. (I imagine it will weather the storm pretty well, but I'm not a lawyer nor would I try to predict the U.S. legal system.) Also, the GPL won't "ensure that your code remains free" any more than a copyright will ensure that your favorite band's newest album won't be shared on Kazaa. It will give you legal recourse, however, if you can prove that someone is in violation. Finally, the GPL is rather restrictive. You might wish to use a BSD style license instead. Really, licensing is a personal choice. Writing your own is probably a very bad idea though. Go to http://www.opensource.org to learn about some good choices. Pick the one that best suits your intentions.

-sauoq
"My two cents aren't worth a dime.";