Video Guide:
Text/Photo Guide:
When you upload files to your library, first click on the + sign in the upper right of your library:
From here, you'll be presented with an uploader to upload new files to your library
At the time of upload you can either upload one file or many files! There's no limit to the total number of files that can be uploaded, but each file has a max size of 100 mb today on Practice
It's nearly the exact same process for uploading a link, but you'll encounter a link input instead of a browse for files input: