This will serve as both a reference for current GMs, and a place for new GMs to get everything they need to start out.
First, check the GM list thread here to see which teams are open and indicate that you are interested in joining. Then send a PM to both of the league commissioners (myself and Randyrocks77) to notify us of your interest. We will speak with you and let you choose your team, then assist you with getting set up.
Once you join, you can use the league site as a point of reference and post lineup changes in the subforum for lineup changes if you don't own the game, which is here. Check the rule book for the correct format for posting lineup changes. The rule book is here. Also notice the sections of the rule book that specify the limits for lineup changes, and other things for anyone that doesn't own the game.
We use OOTP X in this league. If you have a Mac, it will not work. Also, if you have a newer version of OOTP, it will not work. You do not have to own the game to be a part of the league, but you will have a much easier time managing your team. We offer to make changes on behalf of GMs that don't own the game but we put limitations on it so it doesn't take up too much time. When you own the game there is a much much more extensive pool of data available to you about your organization as well as a vast number of advanced options you can set up. If you need a copy of the installer for the game, I have one and I can post it somewhere online for you to download. A license can be purchased in the game once it is installed. The license is only $20.