It depends what kind of traveling you are doing and where you are.
I might be the only one who will say this, but for city maps I love the Mapeasy ones.
But those are only mildly helpful with transportation. Often the place where you are staying has good transportation info/maps—but you have to get there, first.

Stop at Tourist information at the train station and ask for a map. For some cities these maps are excellent (Rome) for others (Paris) they’re only mildly helpful as street maps but they usually have a subway diagram and other helpful transportation information.

See which city maps are available at your local bookstore — compare to the maps in Lonely Planet or the DK series guidebooks.

I’m a little adventurous, so a lot of times I’ll just go with whatever rudimentary map is available in the Rick Steves or Let’s Go book that I’m using. For smaller towns, these can be largely worthless, but like I said… adventure

Really though, these should probably just be your backup. The best course of action, like OldLady says, is to hit up whatever tourist info office is in the local train station.

Though, a few tips I’ve learned over the years: 1) even if a place doesn’t HAVE a tourist information spot (depending on where you are, this is a real possibility), chances are, if they have a train station, they have a map of the town on the wall somewhere. So what do you do? Point your camera at it, set it to the highest resolution and size that you have, and take a picture of it! I can’t tell you how many times this has helped me also 2) CARRY A COMPASS WITH YOU. You’d be surprised how many times you will get turned the wrong way on those wacky European streets. This way, even if you can’t see any street signs, if you have a map, just point your compass north, and walk until you hit something recognizable on your map.

If you have an adress for something specific your looking for (and it’s not a main attraction, espcially shops) google maps works best.

Yeah, assuming you have access to it while over there, though. Again, sometimes I would pull up something on Google Maps or Google Earth and just take a picture of it with my camera. But I guess if you have a Blackberry or something and it works in Europe, you can do it that way

Never would have thought to carry a compass. Makes sense, though. Thanks!

No problem! First time I went over, I decided against it, and then immediately realized how useful it would have been to have one. I’ve used one every year since

Of course the iPhone has a compass built it. When I first heard about the compass on an iPhone I thought it was a pretty dumb idea, but now maybe not so much.

I’ll have to add the compass to the list of things I need to get. It seems the closer the trip gets, the more I procrastinate on dealing with the details. I still haven’t booked accommodations in Florence or Rome or made my Uffizzi reservation. Well, I guess it will all get done or it won’t.

Oh, the iphone. I’m sure I’ll get around to getting one as soon as the next newfangled technological improvement comes along.

I have some Michelin maps, which are good, but are so large they are hard to use outdoors if there is any breeze. I also have some maps printed in booklet form, which solve the wind problem, but I find them a little hard to use as each page is only a few blocks of the city, and its hard to get the bigger picture.

Lately I’ve been carrying a laptop. My browser has an add on program that lets me capture web pages, so that I can access them even when I cannot reach the Internet. Its been very handy, since there are any number of good maps on the Internet.

We have the Michelin maps as well, for France and a few other countries.
The husband likes them but they overwhelm me.
Yes, I’ve gotten us lost a few times.