From MovableType

Movable Type offers an interface for uploading many types of text and image files onto your web server for use on your site. You can upload files to your Local Site Path or any directory beneath it. After you have uploaded a file, you have the choice of either creating a new entry using that uploaded file, or just displaying the HTML used to link to the file.

If you uploaded an image, and your system administrator has installed the Image::Magick Perl module, you have the additional option of creating a thumbnail of the image that you uploaded.

To upload an external file for use on your blog

1. From the main administrative menu of your individual blog, click the link labeled Upload File found in the Posting section of the sidebar navigation menu to open the file upload window.
2. With the upload file window open, click the Browse button to locate and select the file you wish to upload from your hard drive. This button will open up a browsing dialogue box.
3. Once you've located the desired file, double click the file name to select it.
4. With the desired file selected, you can specify a particular upload path if you wish by clicking Set Upload Path. Otherwise, it will be uploaded to your blogs Site Root.
5. Next, click the button labeled Upload to save it to your web server. The resulting page shall provide you with options for using the newly uploaded file if available.
6. Choose the default option to create a new entry immediately using this uploaded file, or select the option to simply show the HTML linking to your newly uploaded file. If you wish to create an entry using this file at a later time, you can simply view the HTML and copy it for later use.
7. Click the button labeled Link if you have downloaded a text file, or choose the appropriate action button (Popup Image of Embedded Image not shown) if you have downloaded an image file. These buttons will return the appropriate HTML surrounding the URL of your newly uploaded file either in the Entry Body field of the new entry screen, or on its own for you to copy and paste where desired.