If you have a lot of files to add to your resource libraries (images, audio, files, etc), simply use the in-page multiple file uploader (found on any page that lets you select files from your library). That way you can just upload the files when you need them. This tool has a nice progress bar to monitor your upload progress for each file.
If you use video on your site, we recommend (require) uploading your videos to Youtube or Vimeo (and embedding the code in your local multimedia record). This saves you a lot of cost for disk and bandwidth usage, it publishes your content to a greater audience, and it encodes your video in multiple formats to support every browser and device.