....and how do you tell the difference?
The best thing I can tell you is to get an app like SystemPanel or Spare Parts
SystemPanel App / Task Manager - Android app on AppBrain
Spare Parts - Android app on AppBrain
These will allow you to see the actual CPU usage of each app. An app that isn't using CPU cycles isn't "running" or using your battery.
Android OS deliberately pre-loads apps into memory primarily for performance (it's faster if they're already there than if you have to load them from storage when you open them) and also leaves them in memory after you "close" them because the process of unloading them actually uses more CPU cycles (and thus battery). It only unloads the app from memory if it needs that memory space for a new app to load into.
Most people use the same apps repeatedly as well, which means in the long run these apps get to just stay in memory all the time, never getting unloaded/loaded/unloaded/etc... not only causing you to have a faster experience, but SAVING battery life.
Now why is an app you have NEVER used like VZ Navigator for example pre-loaded? Well this is almost certainly VZW's fault. They've probably prioritized "their" apps so they will be more likely to be loaded into memory should you choose to try them (and thus give the illusion of being "faster" than some other third party app for example), but this is just a guess.
So, theoretically is a tiny bit of your battery getting used when Navigator or some other crap gets cached into memory because of VZW's efforts? I suppose, but it is a tiny, negligible amount (and Android would have taken a guess and loaded something else in that space anyway).
Bottom line, as long as an app isn't actually chewing up CPU cycles, it's not chewing up your battery. You're spending WAY more of your battery constantly checking to see what's loaded in your memory (and especially if you bother to manually close those things) than your phone spent putting stuff in there.
Don't get me wrong, you SHOULD look into these things every now and again to make sure things aren't misbehaving on your phone. But the point is doing so is a troubleshooting step, not something you should be doing as a normal course of operation. And when you do want to look into what might be chewing up your battery, you have to look at what is using CPU cycles, NOT what's simply sitting idle in memory. If all you're doing is checking what's in memory and then killing that stuff, then you're actually contributing to your battery problem instead of helping it. Sure, you may get lucky and kill an app that is actually misbehaving, but it'll just come right back and start misbehaving again if you don't actually identify which one it is and get rid of it or find out what you can do to correct it (by changing settings within it or updating it to a new fixed version, etc.).
Hope this helps.