I'm assuming you mean in Windows.
If you want to move all the files in the folder you can click Ctrl+a, this selects everything in the folder.
If you want to select a string, such as the first 3, 20, 50, whatever in a row, but not all the pics select the first pic, then hold down shift and select the last pic you want and it selects all the pictures in between.
You can also hold down ctrl and click each file you want and it will select each one you click on long as ctrl is held down.
From there you can drag and drop everything select, or you can right click on any selected picture and hit 'cut' (ctrl-x does the same thing) then go to the folder you want to put them in and right click in it and hit paste (ctrl-p does the same thing).
Cut (ctrl-x) will take the files out of the folder and copy them to your clipboard, so make sure you paste immediately so you don't lose them for good.
You can also right click Copy (ctrl-c) and then paste in the new folder, that way you don't lose anything, but then you have to go back and delete the ones in the old folder, though everything should still be selected when going back to that folder unless you have clicked off of them.