AFAIK Greyhawk does not really have a map of it's own.
It does. Here is a big 1:

@ Tasunke - Check out the rulebooks, because it would take a lot of time to make a proper post about the Greyhawk setting. There are lot of Greyhawk related sites on the net as well. Either way, here is a little info about the history&world of Greyhawk:
http://www.canonfire.com/cfhtml/modules.php?name=News&file=article&sid=863
The World of Greyhawk
The World of Greyhawk setting is as old as D&D itself. The setting was created when Wisconsin wargamer Gary Gygax began modifying the rules for Chainmail, a medieval wargame he had created in 1971 with fellow wargamer Jeff Perren. According to Gygax, he was inspired by some earlier modifications made to the rules by Dave Arneson, but felt those changes didn’t really fit into the game’s framework. Therefore, building onto Arneson’s rules, Gygax began developing both Dungeons & Dragons and the Greyhawk campaign. (5) Much of the activity in Gygax’s campaign initially took place in or near the City of Greyhawk, which would lend its name to the entire setting. (6)
While the first printing of Dungeons & Dragons was released in 1974, the Greyhawk campaign setting did not see print until 1980, when The World of Greyhawk Fantasy World Setting, a folio containing maps and information on some of the setting’s political states, was published. Though various works (supplements, adventures, articles in gaming magazines, and a novel by Andre Norton) making reference to Greyhawk appeared before 1980, this was the first time TSR (the publisher of D&D) had ever released an overview of the setting. In 1983, the World of Greyhawk Fantasy Game Setting, a boxed set containing significantly more information than the folio, was released. Several Greyhawk adventures and articles followed, as well as a line of novels for the setting.(7)
The “world” of the World of Greyhawk setting is “Oerth,” a planet slightly larger than our earth. (8) Though Oerth has four continents, (9) the vast majority of material published for the setting takes place in “the Flanaess,” the northeastern region of the continent of “Oerik,” roughly the size of Europe. Though populated mainly by humans, several other creatures also make their homes in the Flanaess, including dwarves, elves, drow (dark elves), halflings, gnomes, orcs, giants, dragons, goblins, and several other creatures of the D&D game. (10) Most cultures found in the Flanaess resemble those of medieval Europe, though faux Mongol, Arab, American Indian, Gypsy, Aztec, and African cultures are also represented. (11) Notable nations include: the Free City of Greyhawk, a cosmopolitan city-state; Ahlissa and the North Kingdom, feuding successor-states of the Great Kingdom which once ruled much of the Flanaess; the Scarlet Brotherhood, a monastic nation cleaving to a doctrine of racial purity; the Orcish Empire of the Pomarj; the elven nation of Celene; the Empire of Iuz, ruled by a demonic demigod; Keoland, a land where magic is viewed with superstition; and the chivalric realms of Furyondy and Nyrond. (12)
After Gygax left TSR in 1986, few materials for the setting were published. However, in 1988, TSR began releasing a “second” wave of Greyhawk products, beginning with Greyhawk Adventures, the first hardcover for the setting. The setting was converted to the 2nd Edition game rules in 1989 with the release of Fate of Istus, an adventure spanning several cities of the Flanaess. The City of Greyhawk was finally detailed in an eponymous boxed set that same year. (13)
The setting received a facelift in 1991 with the release of the Greyhawk Wars boxed set, which detailed the cataclysmic political changes brought about by a multinational war started by the demigod Iuz. These changes were further detailed the following year in From the Ashes, another boxed set which included a gazetteer and maps showing new political borders. More supplements and adventures supporting From the Ashes followed until 1993, after which the setting was supported solely by occasional articles in Dragon and Dungeon magazines until 1998. (14)
Greyhawk was revived in 1998 by Wizards of the Coast, which had purchased TSR the previous year. The first Greyhawk release from the new owners was the adventure Return of the Eight, which was soon followed by The Adventure Begins, a 1998 setting overview which updated the campaign calendar by six years. (15) Several more Greyhawk products were released until 2000, when Die Vecna Die!, the last adventure for the game’s 2nd Edition, was published.
Greyhawk was far from dead, however. The year 2000 also brought about the release of Dungeons & Dragons’ 3rd Edition (3E), the most comprehensive revision of the rules to date. The new edition also included Greyhawk as the “core setting.” The most obvious result of this was the inclusion of several of the setting’s deities in the game’s “core pantheon.” (16) The same year also saw the release of the Living Greyhawk Gazetteer, the most comprehensive treatment of the setting since 1992, as well as the debut of the Living Greyhawk campaign, a “shared campaign” administered by Wizards of the Coast’s Role-Playing Games Association (RPGA), in which massive numbers of players participate in a version of the setting conceived by the RPGA. (17)
The incorporation of Greyhawk into the core rules and the creation of the Living Greyhawk campaign have, ironically, resulted in that few Greyhawk-specific products have been released by Wizards of the Coast since 2000. Though the RPGA releases hundreds of free Living Greyhawk adventures, few people are allowed access to the entire selection. A wealth of Greyhawk material has appeared in Dragon and Dungeon (currently published under license by Paizo Publishing) over the last three years, but those magazines will be cancelled in September of 2007. (18) However, a new Greyhawk product, Expedition to the Ruins of Greyhawk, is set to be released in August. (19)