This is really handy! You enter the date you plan on making a new queen (grafting or splitting) and a new page pops up telling when crucial milestones occur.
http://www.thebeeyard.org/queen-rearing-calendar/
I'm starting to be a fan of
Expansion Model Beekeeping which basically says, if you want 2 hives you
should probably go in to winter with 4 hives. Much easier to reduce in spring rather than trying to play catch-up and expand.
Ideally, you'd expand by catching swarms. Splitting is another way to expand. It's another way to get a yield off of a hive.