1st, drinks lots of beer....no, just kidding.
First, if you already didn't know, you set up the league in your game with all the bells and whistles set as you like them...
then you need to find a place to park it online - a web host, for which you will also need domain name - like statesleague.com
some hosting sites come as a package deal with the domain thingy.
or...Allsimsbaseball.com is a site with many OOTP leagues parked; the guy that runs it seems quite helpful and sounds like he does most of the heavy lifting for you.
other than that, the manual is pretty good in getting you up and running with your own site.
following all of that, you upload your game file and reports files for others to receive and see.
your league players then download the game file, make their changes and then they upload the game file back to your site...
which you then load into your game so that their changes take place before you sim the next day(s) sim.
in between that you do all kinds of swearing and grumbling because something is always not working the way you expect.
also, take advantage of the forums, if you read enough and weed out the garbage, some of the stuff can help you.
oh, get players to join the league - can be the hardest part.
good luck.
