We are using the Blood Bowl Competition Rules Pack (abbreviated CRP and available for download from Games Workshop), with the three additional teams of Chaos Pact, the Slann and the Underworld (PDF direct download).

How to Create a Team
Under the "Coach Corner" tab, select the "New Team" tab. Enter your team's name and race. Under League/Division, you probably want Division: Painsphere Open. There is also Test Division 1 which is set up for people to play around in, therefore it's not for permamanent teams. Once you click the create button, you should see a green bar with the message, "Request succeeded." Your team exists, but is empty. Click the "Coach's teams" tab above the green bar. This shows the list of all your teams, and should include the team you just made. Click the team's name. You should naw be able to "Hire player" and "Buy team goods" until your roster is filled.

Note that it's probably best to already know your team build before you input it. You can "Un-hire a player" to get your money back on that choice, but I don't see how to get refunds on team goods (Re-rolls, Fan Factor, etc...) without league commissioner intervention. Make a mistake there, and it's easiest to just delete the team and start over.

Once your roster is completed, choose "Set ready state," make sure the "Team ready?" check box is checked, and click "OK."

How to Schedule and Play a Match
Coaches should arrange match between themselves. Once you know a match will be played, e-mail a League Commissioner and they will get the game ready on the website. After the game is played, you may enter the results online. If both coaches can't do this together immediately after the match, one will have to take responsibility for entering the results for both teams.