Summarize the following:
This app is a blue, face-shaped icon on your Mac's Dock. It's in the top-left row of menu items. Doing so invokes a drop-down menu. This option is about halfway down the Go drop-down menu. It resembles a grey box. On most Macs, the hard drive is entitled "Macintosh HD".

summary: Open Finder. Click Go. Click Computer. Double-click your hard drive's icon. Press Shift+ Command+.. This key combination will display any hidden folders in your Mac's hard drive. Any hidden folders or files will appear as grayed-out. This keyboard shortcut can be done from any Finder window. The main Hard Drive folder usually contains hidden system files and folders so you should be able to see this better here when the hidden files are visible (grayed-out). Press Shift+ Command+. again. This will hide the hidden files again, making them invisible.

Summarize the following:
For the last clause of your citation, type "Retrieved from" followed by a direct link to the YouTube video itself. You can get this link by clicking on the "share" icon. Don't just copy the URL in your browser, as it may not match the permalink for the video. Example: "Last name, First initial. Middle Initial." [username]. (Year, month day). Title of video. [Video file]. URL Example: "Apsolon, M. [markapsolon]. (2011, September 9)." NFL Highlights. [Video file]. http://www.youtube.com/watch=VSk8HEk22

summary: Include a direct link to the video.

Summarize the following:
Do so by opening the red Adobe Reader app with the stylized, white A icon. Then click on File in the menu bar at the top of the screen, click on Open..., select the PDF document you want to type on and click on Open. If you don't already have Adobe Reader, it's available for free from get.adobe.com/reader and can be used with Windows, Mac, and Android operating systems. It's the marker icon on the right side of the toolbar at the top of the window. The text is now highlighted. Doing so saves your highlighting.
summary: Open a PDF document in Adobe Reader. Click on the highlighter tool. Position the cursor at the beginning of the text you want to highlight. Click and hold, then drag the cursor across the text. Release the click when you are done. Click on File in the menu bar and Save in the drop-down menu.