This is one of those really basic things for most folks here. We get that. But it's worth a reminder for those new to Android (hi, new folks!), and new to Android 5.0 Lollipop. And so it deserves a quick minute of our time.
Most of what you'll see in the Lollipop developer settings (at least as of the updated preview) is the same as what you'll find in KitKat. Go to Settings>About phone and hit the build number 7 times to unlock things. And most of us won't need to go anywhere near most of the options. (USB debugging really is the only one I ever need to touch.) It is worth noting, however, that you won't find an option to either use the Dalvik or experimental ART runtime. That's because (and, again, those of you in the back of the class should know this already) the new Android Runtime is the default in Android 5.0, and it's been built to run apps compiled for Dalvik as well. This is a good thing.
You'll find some new media options for an experimental HTML5 player and USB audio, some Wifi tweaks, and a few other things that frankly I have no business mucking about with.
Hack responsibly, folks.