If your browser has Flash installed you will see the Flash uploader on entering the Start Import page. Click the 'Upload files' button to start browsing for files to add. You can add as many files as you like.

Once you are happy with your list of uploaded files, click the 'Next' button to start entering your metadata.  Be aware that the metadata will be applied to ALL of the assets that are imported. It is recommended that they are given the Metadata Status 'Incomplete' so that you can use the 'Batch update' facility later to enter specific metadata for each asset.

When you click 'Start import' the import process will begin and you will see a page showing the progress of the import. Once complete, you will be given the option to start a new bulk upload, or perform a bulk update or batch update on the batch you have just imported.