The National Association of Secretaries of State has long had a useful chart on its webpage, giving the dates of presidential primaries. The NASS page is even better and has added a chart on the rules by which each major party chooses delegates. See both charts here.
How about a chart telling us the rules for getting on the ballot in each state? Petititon? Filing fee? Ect, ect.
That would make too much sense. But they don’t want more people on the ballot, so they try to keep that info secret.
The printed January 2008 Ballot Access News has some of that information for presidential primaries, and will be online in a few days.