My oldest league was once a basic keeper league, in which each owner could designate one keeper. We changed to redraft, and everyone has been much happier (tablus rasa
, every season). My advice would depend on whether you're planning a simple keeper league (1 or 2), or a full-on dynasty league.
Whatever you run, the primary component needs to be rewarding owners for finding diamonds in the rough. Say a 12th round pick blows up into a top-10 RB...the owner shouldn't lose their 1st round pick to keep that player next season, they should only lose, say, a 9th round pick the following year, then maybe a 6th round the year after, etc. One league I saw allowed one keeper in exchange for a first round pick, and one "sleeper" like that, and they seemed happy with it.
I've always wanted to do a full dynasty league, but the time commitment would be enormous, and I'm not sure how you would deal with it if any owners leave.
Some links with suggestions:http://www.rotowire.com/football/showAr ... m?id=13514http://www.4for4.com/content/running_keeper_league.php
And a sample league constitution:http://www.keeperleaguegm.com/wp-conten ... y-2009.pdf