The mini player button has moved in iTunes 12. Here are two places you can find it.
How to get into and how of full screen has changed in Yosemite. Here is how it works. And here is how to get out of full screen in the apps where the esc is not working.
When you are running on battery power, this setting can really help save energy when you are surfing the internet using Safari.
Here's how to choose what Spotlight returns when you do a search of your computer.
Choose what icons you want on the right side of your computer menu bar.