If you want to start on a Watchmen HBO timeline:
1903
June 30
Rorschach #3 (pg. 1)
1945
August 7
Watchmen #4, "Watchmaker" (pg. 3)
1950
????
Watchmen #6, "The Abyss Gazes Also" (pg. 3-4)
Rorschach #5 (pg. 10)
1951
July
Watchmen #6, "The Abyss Gazes Also" (pg. 6-7)
1955
????
Watchmen #9, "The Darkness of Mere Being" (pg. 6-8)
1957
????
Watchmen #6, "The Abyss Gazes Also" (pg. 10)
1959
????
Rorschach #5 (pg. 16)
May 12
Watchmen #4, "Watchmaker" (pg. 4-5)
July
Watchmen #4, "Watchmaker" (pg. 6)
August 20
Watchmen #4, "Watchmaker" (pg. 7-8)
November
Watchmen #4, "Watchmaker" (pg. 9)
November 10
Watchmen #4, "Watchmaker" (pg. 9)
November 14
Watchmen #4, "Watchmaker" (pg. 9)
November 22
Watchmen #4, "Watchmaker" (pg. 10)
December 25
Watchmen #4, "Watchmaker" (pg. 11)
1960
February
Watchmen #4, "Watchmaker" (pg. 12)
March
Watchmen #4, "Watchmaker" (pg. 13)
June 3
Watchmen #4, "Watchmaker" (pg. 14)
November
Watchmen #4, "Watchmaker" (pg. 14)
1961
September
Watchmen #4, "Watchmaker" (pg. 14)
1962
May
Watchmen #4, "Watchmaker" (pg. 15)
????
Watchmen #6, "The Abyss Gazes Also" (pg. 10)
1963
????
Watchmen #9, "The Darkness of Mere Being" (pg. 10-12)
September 23
Watchmen #4, "Watchmaker" (pg. 16)
1964
March 13
Watchmen #6, "The Abyss Gazes Also" (pg. 10)
Rorschach #5 (pg. 11)
1965
????
Watchmen #6, "The Abyss Gazes Also" (pg. 15)
Rorschach #2 (pg. 5-6)
Rorschach #5 (pg. 5)
1966
April 14
Watchmen #6, "The Abyss Gazes Also" (pg. 15)
Watchmen #2, "Absent Friends" (pg. 4-11)
Watchmen #4, "Watchmaker" (pg. 17)
Watchmen #9, "The Darkness of Mere Being" (pg. 14-16)
May
Watchmen #4, "Watchmaker" (pg. 18)
1969
????
Watchmen #4, "Watchmaker" (pg. 19)
1970
December 1
Watchmen #4, "Watchmaker" (pg. 19)
1971
January 4
Watchmen #4, "Watchmaker" (pg. 19)
March
Watchmen #4, "Watchmaker" (pg. 19)
????
Rorschach #5 (pg. 12-15)
May
Watchmen #4, "Watchmaker" (pg. 20)
June 29
Rorschach #5 (pg. 18)
Watchmen #4, "Watchmaker" (pg. 20)
Watchmen #2, "Absent Friends" (pg. 12-15)
1973
January
Watchmen #9, "The Darkness of Mere Being" (pg. 19-21)
1975
January 20
Watchmen #4, "Watchmaker" (pg. 21)
????
Watchmen #4, "Watchmaker" (pg. 21)
Watchmen #6, "The Abyss Gazes Also" (pg. 18-26)
1977
????
Watchmen #2, "Absent Friends" (pg. 16-18)
Watchmen #4, "Watchmaker" (pg. 22)
August 3
Watchmen #4, "Watchmaker" (pg. 23)
1981
May 31
Watchmen #4, "Watchmaker" (pg. 24)
1985
August
Watchmen #4, "Watchmaker" (pg. 24)
October
Watchmen #2, "Absent Friends" (pg. 21-23)
October 12
Watchmen #1, "At Midnight, All the Agents..." (pg. 1-13)
October 13
Watchmen #1, "At Midnight, All the Agents..." (pg. 14-26)
October 16
Watchmen #2, "Absent Friends" (pg. 1-4, 11-12, 15-16, 18-21, 23-28)
October 19
Watchmen #3, "The Judge of All the Earth" (pg. 1-21)
October 20
Watchmen #3, "The Judge of All the Earth" (pg. 22-28)
Watchmen #4, "Watchmaker" (pg. 1-3, 5-6, 11-12, 17, 20, 22-28)
October 21
Watchmen #5, "Fearful Symmetry"
October 25
Watchmen #6, "The Abyss Gazes Also" (pg. 1-8)
Watchmen #7, "A Brother to Dragons" (pg. 1-15)
October 26
Watchmen #7, "A Brother to Dragons" (pg. 16-28)
Watchmen #6, "The Abyss Gazes Also" (pg. 9-13)
October 27
Watchmen #8, "Old Ghosts" (pg. 1-5)
Watchmen #6, "The Abyss Gazes Also" (pg. 14-16)
October 28
Watchmen #6, "The Abyss Gazes Also" (pg. 17-18, 21, 25-28)
October 29
Watchmen #8, "Old Ghosts" (pg. 6-7)
October 30
Watchmen #8, "Old Ghosts" (pg. 9)
October 31
Watchmen #8, "Old Ghosts" (pg. 10-28)
Watchmen #9, "The Darkness of Mere Being" (pg. 1-6, 8-10, 12-14, 16-19, 21-28)
November 1
Watchmen #10, "Two Riders Were Approaching..." (pg. 1-22)
November 2
Watchmen #10, "Two Riders Were Approaching..." (pg. 23-28)
Watchmen #11, "Look on my Works, Ye Mighty..." (pg. 6, 9, 13, 20, 23-28)
Watchmen #11, "Look on my Works, Ye Mighty..." (pg. 1-5, 7-8, 10-12, 14-19, 21-22, 24-28)
November 3
Watchmen #12, "A Stronger Loving World" (pg. 1-27)
December 25
Watchmen #12, "A Stronger Loving World" (pg. 28-30)
1987
January 1
Watchmen #12, "A Stronger Loving World" (pg. 31-32)
1988
????
Rorschach #2 (pg. 7-8)
2009
????
Rorschach #3 (pg. 3-5, 7-9)
Rorschach #5 (pg. 11)
2013
????
Rorschach #3 (pg. 11-14)
2015
????
Rorschach #3 (pg. 16-19)
2016
????
Rorschach #4 (pg. 2-13, 16)
November
Rorschach #4 (pg. 17)
2017
????
Rorschach #4 (pg. 18-19)
2019
????
Rorschach #2 (pg. 15)
November
Watchmen 1x01, "It's Summer and We're Running Out of Ice"
Watchmen 1x02, "Martial Feats of Comanche Horsemanship"
Watchmen 1x03, "The Was Killed by Space Junk"
Watchmen 1x04, "If You Don't Like My Story, Write Your Own"
Watchmen 1x05, "Little Fear of Lightning"
Watchmen 1x06, "This Extraordinary Being"
Watchmen 1x07, "An Almost Religious Awe"
Watchmen 1x08, "A God Walks into a Bar"
Watchmen 1x09, "See How They Fly"
2020
????
Rorschach #2 (pg. 7, 18)
Rorschach #2 (pg. 9-10)
Rorschach #5 (pg. 1-2, 4, 6-7, 9, 13-15, 18-19)
Rorschach #2 (pg. 2-3)
Rorschach #5 (pg. 20-21)
October
Rorschach #1 (pg. 8)
Rorschach #2 (pg. 19-21)
Rorschach #2 (pg. 16)
Rorschach #3 (pg. 1, 3, 19-21)
November
Rorschach #1 (pg. 6)
Rorschach #1 (pg. 4, 11-15, 20-21)
Rorschach #5 (pg. 7-9)
Rorschach #1 (pg. 1-10, 15-21)
Rorschach #2 (pg. 1-5, 7-8, 11-19, 22)
Rorschach #5 (pg. 3-4)
Rorschach #3 (pg. 2, 6, 10, 15, 21-22)
Rorschach #4 (pg. 1, 6-8, 11-12, 14-16, 20-22)
Rorschach #5 (pg. 1-3, 5-6, 9-12, 15-21)
Rorschach #6 (pg. 3, 8, 12, 17, 20-21)
Rorschach #7
Rorschach #8
Rorschach #9
Rorschach #10
Rorschach #11
Rorschach #12
I haven't actually gotten to Rorschach yet. Lots of flashbacks, no dates. I'm looking through it, will update when done.
Edit: half done with Rorschach.