Ideally, this won't be a discussion about the relative merits of ppr and standard scoring or other issues of personal preference. Just things that any new dynasty owner should know before jumping into a league with strangers on the internet. Some of these things (such as bylaws) will be dynasty-specific; others may be more universal.
ETA: Thanks for the vote of confidence, MEuRaH. I'm a firm believer in wisdom of the crowds, so I hope this thread can be a platform for more than one voice. But I'll get the ball rolling with a few thoughts.
New Leagues
1. Leaguesafe: I recommend it for leagues with any substantial amount of money in play. Actually, I use it for almost all the leagues I run because it's easier for me to keep track of payments on Leaguesafe than with Paypal. Also, if there's real money at stake, be sure to ask that payouts be governed by majority vote, not commissioner control.
2. Bylaws: Check to make sure the bylaws are sensible and thorough. Here's a (non-comprehensive) checklist of issues that should be addressed in the bylaws:
- Tiebreakers -- final standings and playoff games
Rule changes -- how and when can the league/commissioner change the bylaws?
Trade vetoes -- what are the criteria for veto (collusion only; gross imbalance; integrity of the league; etc.)?
Division realignment (if divisions exist) -- can divisions be realigned? If so, how? When?
Tanking -- what are the consequences?
Existing Leagues
1. Message Boards: Check out the league message board from this year and the previous years. This is often where grievances are aired, so you can learn a bit about the commissioner's management style here.
2. Check for turnover: Look on the past league sites to see how many teams have changed from year to year. There's always going to be some turnover in dynasty leagues, but if half the league bolted last offseason, that's a red flag.
3. Just ask: Ask why there is an opening in the league. If the commissioner goes on a rant about what a pain in the bleep that guy was, that could be a sign that the commissioner is actually part of the problem.