I run a second edition campaign using the Greyhawk gods for a world of my own design. I'm currently adapting the first adventure from Tales of the Outer Planes ("A Simple Deed, Well Rewarded") for my players, substituting Greyhawk gods for most of the gods in the adventure. I wanted to use Norebo in the adventure, but I'm having trouble finding information on his abode.
Wikipedia's entry on Norebo does not give his homeplane, and neither does the Norebo entry on this site. Dragon #86 lists Norebo's homeplane as Pandemonium. Oerth Journal #15, on the other hand, says:
Hazard.” This realm is located near the gatetown of Glorium and
the Plane of Ysgard. The center of the realm is a huge town of
gambling halls and inns. There are numerous circus tents, open
stable areas and fast moving rivers surrounding the town. The town
is set into a valley with high-reaching peaks that many brave souls
attempt to climb. There is no pass entering into the Realm; only
by coming over the mountains can one reach the town. Regardless
of accessibility, the petitioners in the town never want for food or
other supplies. The shops are always full, as are the gambling halls.
People from all over the multiverse come here to try their luck at
the tables. Many a great fortune has been won by those that are
brave or foolhardy enough to make the trek into and out of the
realm.
In addition, according to a random website I found, Norebo is in Limbo:
Norebo exerts his influence to bring sense and order to a small region of Limbo which he calls his own. The result is a palatial gambling house, a casino staffed by einheriar, in which all games of chance are offered for any stakes, including those of powers.
Has Norebo ever been addressed in any Planescape books? Can anyone clear this up for me?
No, Planescape didn't mention him. On Hallowed Ground mostly didn't bother with Greyhawk gods below intermediate level (because there are so many Greyhawk gods, and only so much space in the book).
Warriors of Heaven assigned realms to a number of previously unrealmed deities, but it concentrated on those of the Upper Planes. And it did kind of a bad job at it, arbitrarily putting some of them in already-defined sites.
As far as I know, the Dragon #86 article by Len Lakofka is still considered canonical (not the stats, obviously, or the priest rules), so I would say he lives in Pandemonium unless there's been some update I'm unaware of.
Although, note that Lakofka's article said he was chaotic neutral with evil tendencies and made him a patron of assassins, and that this isn't something that's been followed up on by any subsequent source. Although everyone kept Lakofka's LN (LE) alignment for Wee Jas, everything since has said that Norebo is plain CN. So Limbo might be more appropriate.
I think he's much too chaotic for the Outlands. The only advantage of putting him in the Outlands is it makes his gambling hall more accessible to planewalkers, which I suppose isn't anything to be sneered at.