arcgis-desktoparcmapcartographylegend
Do to various limitations I almost always create static (graphic) legends but I do have the occasional map where impeccable cartography is secondary to functionality hence a dynamic legend is acceptable.
I am Currently working on a map where I want the legend to be 4" wide with one legend column. I need to show very long layer names in the legend but I don't know how to force labels to roll to multiple lines dynamically.
Several ways...
In the layer properties dialog on the general tab you can change the name and description.
In the table of contents select the name and click again. You will be able to type anything you want.
You should also note that when in the legend if you select the layer and then the style button changing the style to layer name with label, heading with label, heading with label description. So on so forth...
In 10.1 you have a lot more control over legends. You should be able to wrap both the labels and the description using the Text Wrapping option in the Layout tab (see below)
If that still doesn't work you can manually force the line breaks using the Symbology tab in the Layer Properties. If you right click each of your unique values and select Edit Description you can enter text (See the next image)
Once in the edit description you can put in line breaks by hitting CONTROL ENTER to get a new line.
Also check this out for more info: Arc 10.1 Legend Help
That should give you enough options to get the legend the way you want it.
Best Answer
Could you use Descriptions? They can handle multiple lines in the legend.