Pacific Coast League - Since 1903
"I didn't say the things I said." - Yogi Berra

The season id is a five digit number that is very easy to find.
Step One: Navigate to your league home page and then to the draft page.
Step Two: Once you are on your league's draft page, look at the URL in you browser's navigation bar. It should look something like this:
http://www.csfbl.com/draft.asp?seasonid=12275
The five digit number you see at the end of the URL is your season id.