Загрузка файла на сервер

http://stackoverflow.com/questions/15772394/how-to-upload-display-and-save-images-using-node-js-and-express

Документация по Multer
https://github.com/expressjs/multer

Мульти-загрузка
https://codeforgeek.com/2016/01/multiple-file-upload-node-js/

https://coligo.io/building-ajax-file-uploader-with-node/

https://habrahabr.ru/post/229743/

еще https://codeforgeek.com/2014/11/file-uploads-using-node-js/

Angular + NodeJS
http://code.ciphertrick.com/2015/12/07/file-upload-with-angularjs-and-nodejs/