Thanks, everyone, for the replies so far. I've been noticing a trend in pro-level cartography software: it is designed to be used with real-world data. This tends to put a damper on things for those of us who map imaginary worlds. The "best" program I've so far found to bridge that gap is Ocad (http://www.ocad.com/en/index.htm). As luck would have it, however, I know very little of Ocad, except that I love its road lay-out feature (it has automatic intersection, which would otherwise have to be done manually, it seems, in software such as Illustrator).

As far as the types of maps I’m going for, I like the old city maps that show entire city blocks in relief relative to the roads, or ones that each building in relief, too. Here’s a fantasy example of my desired end result: http://www.wizards.com/dnd/images/ma...f2y9f2_ppi.jpg, which I found on this page: http://www.wizards.com/default.asp?x=dnd/mw/20061101a

And here is a link to a screenshot from the aforementioned Ocad that shows a city in the style I’d like (I’ve seen this style in many different pocket travel guides): http://www.ocad.com/en/ocad_screenshots.htm. I’ve found it very difficult to use Illustrator to draw boxes like those from the example on the Wizards’s site that are not only not uniform, but that are aligned to the streets they face. Ocad suggests you can do it with their software, but I don't know if this is industry-standard stuff (and I don't think it is). Maybe, as RobA said, I should remember that paper-and-pen skills are really where it all begins....