Preface (p. 4)
pp. 4-5, [map]: The page gutter obscures key parts of the Storm Coast map, particularly the area between Neverwinter and the High Road. The map on p. 5 of Lost Mine of Phandelver (in the Starter Set) fills in some, but not all, of the missing map parts.
In the Moonshae Isles, the large northern island should be labeled "Alaron" (see p. 68). "Omans Isle" should be "Oman's Isle" (see p. 69)
See the note to p. 90, Forest of Wyrms, about Ss'that'tiss'ssun.
See the note to p. 93, The Uthgardt Tribes and Their Territories, about the Cold Wood.
A poster map of the region would have been helpful, as would at least a small world map showing locations outside Faerun proper. The following map (from 4E?) shows more of the Realms, though at the cost of some detail: https://vignette.wikia.nocookie.net/forgottenrealms/images/a/a0/Faerun_map.jpg/revision/latest?cb=20080923050218
Chapter 1: Welcome to the Realms (p. 7)
No notes.
Chapter 2: The Sword Coast and the North (p. 43)
p. 50, [map of Mirabar and environs]: See the note to p. 93, The Uthgardt Tribes and Their Territories, about the Cold Wood.
pp. 50-51, Mirabar: In the fifth paragraph, delete the initial quote (') of the second sentence.
pp. 59-60, Citadel Adbar: In the first sentence, change "Ice Mountains" to "Ice Spires". (See the map on pp. 4-5.)
pp. 61-62, Gauntlgrym: A little over two lines in the first paragraph are in a larger font size than the rest of the text.
pp. 62-63, Ironmaster: In the fifth paragraph, change "to tundra" to "the tundra".
pp. 66-67, Mintarn: In the eighth paragraph, "Neverwitner" should be "Neverwinter".
p. 68, [map of Moonshae Isles]: None of Alaron's settlements are marked on the map (or on the map on pp. 4-5, which doesn't even label Alaron). "Omans Isle" should be "Oman's Isle", per the main text on p. 69.
p. 68, Alaron: The text of the first paragraph mentions "Dornall Forest", but the map (same page) spells it "Dernal Forest". Which is correct?
p. 69, Norland: In the second paragraph, "Said to blessed" should be "Said to be blessed".
p. 69, Oman's Isle: Delete the "is" after "a blasted place".
p. 69, Gundarlun: Change "ship s" to "ships".
p. 86, High Forest: In the ninth paragraph, "Most the peaks" should be either "Most peaks" or "Most of the peaks".
p. 88, Secomber: In the last sentence, insert "the" before "northern edge".
p. 88, [map of High Moor and Najara]: See the note to p. 90, Forest of Wyrms, about Ss'that'tiss'ssun.
p. 89, The Court of the Serpent King: In the third paragraph, "the Dhosun's" should be "Dhosun's"; capitalize "forest".
p. 90, Forest of Wyrms: The text states that Ss'that'tiss'ssun lies in the northern fringes of the forest, but the maps on pp. 4-5 and 88 place it about 50 miles away, halfway to the Marsh of Chelimber.
pp. 91-92, Rural Settlements: In the first full paragraph on p. 92, "mine have been" should be "mine has been".
p. 93, The Uthgardt Tribes and Their Territories: The "Glimmering Wood" or "Glimmerwood" mentioend under Black Lion and Red Tiger and Sky Pony is labeled "Cold Wood" on the maps on pp. 4-5 and 50.
Chapter 3: Races of the Realms (p. 103)
p. 106, Rare Elf Subraces: Wizards of the Coast's "Unearthed Arcana" series has introduced 5E stats for the avariel, sea elves, and wild elves (called grugach in Greyhawk); for details, see "Elf Subraces" (11/13/2017): http://dnd.wizards.com/articles/unearthed-arcana/elf-subraces
Star elves are probably eladrin; see "Unearthed Arcana: Eladrin and Gith" (9/11/2017): http://dnd.wizards.com/articles/unearthed-arcana/race-options-eladrin-and-gith
Lythari have not yet been adapted to 5E.
Chapter 4: Classes (p. 121)
No notes.
Chapter 5: Backgrounds (p. 145)
Many (but not all) of these backgrounds are essentially variants of backgrounds from the Player's Handbook, with new features and sometimes one skill changed.
Commentary along the lines of the Appendix would be useful here, to provide advice about altering these backgrounds to use in other worlds.
Appendix: Class Options in Other Worlds (p. 155)
No notes.
Index (p. 158)
No notes.