I've done a fair bit of walking in Italy, though not the specific walk you're talking about.
A few general points though.
Wildcamping isn't the done thing. I'm sure it's possible in some places, but the Alps are generally pretty populated places and rifugios are plentiful. Most Italian rifugios I've been to do excellent food at decent prices, you're usually never further than a couple of hours walk from one.
Most trails are well marked and well signposted. Often signs will indicate how long it will take to get to a particular point rather than the distance. In my experience these times have been spookily accurate.
Trails usually follow fairly obvious lines, particularly in the Alps. I've yet to encounter areas where losing the trail is likely or nav would be a issue (in normal visibility/weather/circumstances).
Therefore I've managed okay without comprehensive mapping. Kompass maps have been enough for me. and they are easily available in Italy. Not that I'd advise going out without a good map, but it's been less of an issue than in the UK because of the nature of the terrain and the quality of trail marking.
That said, here's a signpost I enountered down in Abruzzo:
Edited: 13/06/2012 at 10:34