Geez Psyekl, it doesn't seem to matter what type of map you do (dungeon, building, city), they all keep turning up cool
If you do get close to publishing, it wouldn't hurt to talk to Cartographers who have already "made it" (as in being published in a commercial product) for pointers and advice. Three good ones I can think of off the bat are Christopher West (see Dungeon magazine, Wotc and the Game Mechanics City Quarters series--especially Thieve's Quarter) at
http://www.velocity.net/~westwinds/; Craig Zipse (whose done a lot of work for Kenzer and Company (Kalamar), Wotc, 7th Sea, Shadis and Dungeon Magazines) at
http://www.craigzipse.com (you can check out a broad selection of his work at
http://www.craigzipse.com/ mapdungeon.htm; and Keith Curtis at
http://www.kacurtis.com (his City of Tallon at
http://savageearth.net/Tallon-Rendered.html is one of the most insane pieces of Cartography I've ever seen. Homeslice either has some serious drafting OCD or went into overdrive using the autofill function in his cad program

. His world and continent maps are something special to behold as well, check out
http://www. baegtobar.com/tier_3.php?page=atlas ).
West and Robert Lazzeretti (who does a lot of work for Dungeon and Wotc) sometimes hang out at the Paizo.com messageboards and seem to be very approachable and courteous. While you're there, you can check out the free Dungeon Magazine issues map downloads at
http://paizo.com/dungeon/news for a broad cross section of the types of cartography that Dungeon is using (and they use quite a bit).
One of the things that they've been publishing recently that I really like are what I call "cartographic paths". The paths are a series of generic maps that can be used as stand alones but have pointers to other maps that are published in previous or later issues (check the last page of each Dungeon supplement for the maps, they should be labeled Maps of Mystery--one of my favorites is a series of maps of a subterranean lost world formed in a glacier by steam from a volcano). If you go commercial you might want to try some variation of the idea for yourself, so far, it's been going over really well.
Keep at it and I hope you find something of use in the above Psyekl.