How do you copy and paste into Git Bash

It's not really a function of git, msys, or bash; every windows console program is stuck using the same cumbersome copy/paste mechanism for historical reasons. Turning on QuickEdit mode can help -- or you can install a nice alternative console like this one, and change your git bash shortcut to use it instead.

Aside from using the edit menu commands, you can directly paste into the git bash window using the keyboard shortcut, Insert.

Press Insert.

Also, to copy from the window, try clicking the console's window icon (topleft) and choosing Edit -> Mark, then drag a box on the text, then press Enter. (You can also paste via the window icon menu, but the key is faster.)

UPDATE

Starting from Windows 10 the CTRL + C, CTRL + V and a lot of other feature are implemented in conhost.exe so they should work with every console utility on Windows. (You have to enable Properties -> Option tab -> Quick Edit Mode)

Ref: http://blogs.windows.com/buildingapps/2014/10/07/console-improvements-in-the-windows-10-technical-preview/

Copy:

Long-term solution: Click on Topleft icon > Defaults > Select "QuickEdit Mode" under "Edit Options" > Okay

Then select the text you want to copy. Press Enter

Short-term solution: Click on Topleft icon > Edit > Mark. Press Enter.

Paste:

Press Insert

(If the "QuickEdit Mode" is on, Right clicking might work too.)