How do i select a huge number of songs to add to a playlist in iTunes?

put all of the files into a directory, and then just go to file and import files to playlist.

if they're all grouped together, press shift and left click on the first song on the list and the last song on the list and it will select the songs and the ones in between. then file, create playlist from selection.

Assuming the songs are already in the library and are one after another in the list, just click the first one, hold down the Shift key, and click on the last one you want to add. Then drag it over to the playlist. If there are some you don't want, it might be easier to delete them out of the playlist once they have been dragged over. Perhaps if they are not altogether some type of sort would put them together? I use the rating system as I listen to songs so at anytime I can use it to sort the ones I really liked from those I do not. Hope this helps.

Many ways. Here is one: click on the first song you want to add. Then, hold 'shift' and click on the last song on the list you want. All songs in between are now highlighted. Drag them into your playlist! If there are songs in between that you do not want in the list, hold 'ctrl' and click those songs and they will be unselected.

If they share something in common (artist, album, etc.) make a Smart PlayList. E.g., all songs with Warren Haynes would be all of Gov't Mule + all of artist Warren Haynes. Good luck!