Discovered Attacks, Discovered Checks, Double Checks

I've started the first circle of what will comprise the next three chapters of Reinfeld's 1001 Winning Chess Sacrifices & Combinations. After finishing my 7th circle on the Double Attack, I can say I finally get the idea of the many possible ways double attacks can occur during games. Boy, does my head hurt! Anyway, my goal is to complete 7 circles on these chapters by next Sunday, although I know it will be a challenge fitting everything in when I've got a 2 day tournament plus an OCL game plus an STCBunch Open game to fit in as well. We'll have to see how it goes!