not counting Legend of the Twilight, what .hack book should I start with???

[Darkastral]

I have .hack// Legend of the Twilight v.1-3, and i noticed that there are also paperback books(not graphic novels) in the manga section next to them

however, I don't know which of them to start with...

[Kaz]

.hack//Legend takes place a while after .hack//SIGN, so that should tell you pretty well which one to start with.