Selecting Files Without the Mouse

You can select all files in a particular folder by pressing Control + A.
But what if you want to select only certain files?
To select files that are next to each other in a list, select the first file by arrowing to it, then hold down Shift key and Arrow Down selecting multiple files as you go. When all the required files are selected, let go of the Shift key and continue.
To select multiple files that are not next to each other in the list, select the first file by arrowing to it, then hold down the Control key and keep it held down throughout. Arrow to the next file, press the Spacebar to select it. Continue to hold down the Control Key. Arrow to the next file and press the Spacebar to select it. Repeat until you have the required files selected, then you can let go of the Control key and continue.