Although I could not make it all the way through Flashpoint, you may want to. Here is one reading order I found works quite nicely:

  1. Booster Gold #44
  2. Flashpoint #1
  3. Secret Seven #1
  4. Batman – Knight of Vengeance #1
  5. Abin Sur #1
  6. The World of Flashpoint #1
  7. Deathstroke & the Curse of the Ravager #1
  8. Emperor Aquaman #1
  9. Citizen Cold #1
  10. Frankenstein and the Creatures of the Unknown #1
  11. Wonder Woman and the Furies #1
  12. Legion of Doom #1
  13. Grodd of War (one shot)
  14. Kid Flash Lost #1
  15. Lois Lane and the Resistance #1
  16. Reverse Flash (one shot)
  17. The Outsider #1
  18. Deadman and the Flying Graysons #1
  19. The Canterbury Cricket (one shot)
  20. Hal Jordan #1
  21. Green Arrow Industries (one shot)
  22. Project Superman #1
  23. Booster Gold #45
  24. Flashpoint #2
  25. Flashpoint #3
  26. Secret Seven #2
  27. Abin Sur #2
  28. Batman Knight of Vengeance #2
  29. Booster Gold #46
  30. Emperor Aquaman #2
  31. Frankenstein and the Creatures of the Unknown #2
  32. Deathstroke and the Curse of the Ravager #2
  33. Citizen Cold #2
  34. The World of Flashpoint #2
  35. The Outsider #2
  36. Wonder Woman and the Furies #2
  37. Hal Jordan #2
  38. Legion of Doom #2
  39. Deadman and the Flying Graysons #2
  40. Kid Flash Lost #2
  41. Lois Lane and the Resistance #2
  42. Project Superman #2
  43. Flashpoint #4
  44. Batman – Knight of Vengeance #3
  45. The World of Flashpoint #3
  46. Deathstroke & the Curse of the Ravager #3
  47. Secret Seven #3
  48. Booster Gold #47
  49. Frankenstein and the Creatures of the Unknown #3
  50. Emperor Aquaman #3
  51. Deadman and the Flying Graysons #3
  52. Citizen Cold #3
  53. Wonder Woman and the Furies #3
  54. Abin Sur #3
  55. Legion of Doom #3
  56. the Outsider #3
  57. Lois Lane and the Resistance #3
  58. Hal Jordan #3
  59. Kid Flash Lost #3
  60. Project Superman #3
  61. Flashpoint #5