There are times when you may need to upload an images, pdf or any other type of file to your site. Luckily, Joomla has a built in tool for uploading your files. This tool is called the Media Manager.
To get to the Media Manager, login to the backend of your site (/administrator) and click "Media Manager" from the "Site" drop down menu.
Once there, you willl have the ability to upload files, create and organize folders and delete files.
To upload a file, simply hit the "Browse" button at the bottom of the page. Select the file from your computer and upload it to the directory you would like.
To create a folder, you the form at the top of page. Simply type in the name of the folder you would like to create and hit "Create Folder".
To delete a file, hit the checkbox next to the file you would like to delete and hit the "Delete" button at the top right of the page.
Its that simple. If you are having a hard time figuring this out, you can hit the "Help" button.