The update will be gradually rolled out to Verizon customers rocking the Samsung Galaxy S4, so it may be a while before getting your Lollipop fix. Your phone will notify you when the update is available for your device, but if you're feeling impatient, you can manually check for updates by going to Settings -> About Device -> Software Update -> Check for Updates.
The goodies introduced by Android 5.0 Lollipop include an updated TouchWiz interface with Material Design touches, an improved lock screen, and a new multitasking screen. For a complete changelog, check out the source link below.
If you're saddened that Verizon didn't update the Galaxy S4 straight to Android 5.1 Lollipop, you should know that you're not missing on an any major new features. Android 5.1 Lollipop is probably the least important Android update in this regard, as the 5.1 version of Android is mostly focused on fixing bugs that got introduced with the 5.0 version, but manufacturers are able to bake these bug fixes in their implementation of Android 5.0 anyway.