Just browse the boards every day and try to solve the more algorithmic-style questions without looking at the code people have posted. Then compare your code to theirs. A week or two of this will give you a fairly good grasp of Perl.

By the way, the simplest way to remove trailing newlines from an array is:

chomp for @arr;
[download]

You could also use chop, substr, or s///, but chomp has the best combination of speed and flexibility for this task.