Anything in white is non-skippable, red is personally recommended but non-essential.

Marvel Knights/Marvel Boy Genesis Edition(2000)

Not an actual comic, just a preview for Marvel Boy (and Marvel Knights). Nonetheless I like it and want you to see it. All pages with Noh-Varr can be found here.

Marvel Boy (2000) #1-#6

His first actual appearance. His origins and such, absolutely essential. Also the first appearance of Oubliette, who will come back.

Civil War: Young Avengers & Runaways #2-#4

First time he meets the Young Avengers. Not super important story-wise but I like the YA so you should read it.

New Avengers: Illuminati (2007) #4

Cute little oneshot, one of the only times Jim Cheung ever drew him. Kinda important to his character.

Secret Invasion: Who Do You Trust? (2008) #1

Truly the last time they truly let him be a little evil, I thought it was a lot of fun.

Migty Avengers (2007) #19

Kinda essential for his (early) characterization. Sets up an interesting narrative that goes nowhere. This happens all the time for Noh get used to it.

Secret Invasion (2008) #6-#7

He really doesn't do a lot, just kinda aura farms and looks beautiful.

Dark Avengers (2009) #1-#4

His first issue as Captain Marvel. Super interesting the way he's portrayed here, really never touched on again. Truly the most he gets to do during Dark Reign. He hangs out with the Dark Avengers and gets beat up and stuff.