Upload a file
From Georgetown University Commons Knowledge Base
WordPress will accept a number of uploaded file types, including documents (.doc), PowerPoints (.ppt), PDFs (.pdf), images (.jpg, .png, .gif) and some audio and video formats (.m4a, .mp4). A full list is available here. Please keep in mind that the maximum upload size of a single upload is 25MB.
The simplest way to upload a file is while you're writing a post. First, position the text cursor where you'd like a link to your uploaded file to appear in the editing box. Beneath the input box for your title, you will see an "Add Media" button. Clicking on this button will bring up a window where you can select a file from your computer to upload.
Once the file has uploaded, you will automatically have the ability to change the title of the item (and add a caption to your photo upload) as well as a description and more. Make sure that the "Link URL" field is filled. If there is nothing in the field, click the "File URL" or "Post URL" button beneath it. A file URL provides a link directly to the file, whereas a post URL creates a new page within the blog which contains the link for the document. Once the "Link URL" field is filled, click "Insert into Post" which should, as the button describes, insert a link to the document into the post.