It's better to update regularly, rather than wait till you have dozens of updates, because updates are more likely to hang when there are a bunch. That said, my husband never updates his iPad, which he doesn't use much, so I update for him every once in a while, and he's usually got dozens to update by the time I remember.
When there are dozens and they hang, I just look for progress in a few updates and if I see none, then I repeatedly return to the App Store app and tap on Update All. Usually, a few apps finish updating each time I do that, and eventually all are updated. It's a pain, though, because you have to keep checking them. On my iPads, I update every few days or so, it seems, and my few updates rarely hang.
Of course, your wifi connection is one variable. If you've got a slow connection and a bunch of apps to update, my hunch is that you're more likely to get hung up. So again it's better to update more frequently.
