Snipping Tool

To open the Snipping Tool, press the Start key, type snipping tool, and then press Enter. (There's no keyboard shortcut to open Snipping Tool.) The following box opens, but just click enter.

This is the start key on a Windows computer.

This box will open. To choose the type of snip you want, select Mode (or, in older versions of Windows, the arrow next to New), and then choose Free-form, Rectangular, Window, or Full-screen Snip. When making free-form or rectangular snips, use your mouse to select the area that you want to capture.

To take a new screenshot using the same mode you used last, select New.
Use the Save and Copy buttons at the top of the snip to save or copy it to the clipboard.

I usually save mine and give them a name, or if I want to mark them up. I open them in Paint by clicking Paste on a new document in Paint.