Reddit mentions of The Lost Scrolls: Earth (Avatar)

Adding to this bit by HeirToPendragon:

> The Lost Adventures is a collection of official comics from the series that were put in various other places (like Nick Mag). A few tell stories about what happened between seasons.

"The Lost Adventures" also includes the comics that were bundled with the DVD releases (of the non-boxed set variety), like the "Private Fire" comic which came with the Season 3 DVDs. Also, the comics collected in this book are grouped by season, which helps if you want to read them in the chronological order of the show. "The Lost Adventures" is a pretty good collection since it incudes so many comics (it is 240 pages long) and it spans all three seasons of the show, so if you only get one book to start with, this is the one to get.

The four "Lost Scrolls" books (Water, Earth, Fire, Air; alternatively, I think this one book collects all four) include some background information about the four nations in the world of Avatar as well as some first-person stories from Season 1 (basically, some episodes told from the perspective of some of the characters).

The "Earth Kingdom Chronicles" (titles start with "The Tale of [insert character name here]", available for Aang, Katara, Sokka, Toph, Azula, Zuko; I think this one collects some but not all of them) are similar, but for Season 2 and they don't include background info, just first-person perspectives of the episodes. Basically, you follow the individual characters through Season 2.

There's also three little comics set during Season 3 ("Aang's School Days", "Sokka the Sword Master", and "Love Potion #8"). I've heard these aren't that good, but they exist so I'm mentioning them.

"Sozin's Comet" is a novelization of the series finale (the four "Sozin's Comet" episodes).

The new comics, starting with "The Promise, Part 1", are set after the end of Season 3, and those will start coming out early next year.

If you want to read all these Avatar books more or less in chronological order, you'd start with "The Lost Scrolls", then continue with the Season 1 comics in "The Lost Adventures", move on to the "Earth Kingdom Chronicles", then the Season 2 comics in "The Lost Adventures", then the three short Season 3 comics, then the Season 3 comics in "The Lost Adventures", then the "Sozin's Comet" book, then "The Promise" and all that comes after.

And, of course, there's also The Art of the Animated Series, but that's not a graphic novel and would be more for you or for your son when he's older. =)

Edited to add links.