Creating word list from document

I'm trying to find an efficient way of learning vocabulary in new languages. I'd like to be able to create word lists using files that contain books. I'm new to Linux, any help much appreciated. I would like to: * have a command that will take as input a text file (txt format for example) and output another file that contains a list of all individual words in the first file. * The new file should be ordered alphabetically and contain no duplicates (each word should be included only once.) * Ideally, the command should also be able to check against a second file and avoid repeating any words contained in that file. (So that I can create a file or words I already know and that are not repeated.) Is there a suitable command to do this?