File Extensions you should know:

.doc, .docx MS Word Document .abw Abiword document .xls, .xlsx Excel Document .ppt, .pptx PowerPoint document .exe Executable document (program) .jpg, .gif,.bmp image .mp3, .mp4 .wav, .wma audio .wmv, .mov, .mp4, .mpg video .html hypertext markup language (web page) .txt text document (Notepad) .pdf portable document file format (Adobe Acrobat)

Links to sites listing file extensions (there are LOTS if them):

http://en.wikipedia.org/wiki/List_of_file_formats_(alphabetical)

http://filext.com/

http://www.file-extension.com/

http://www.sharpened.net/helpcenter/extensions.php

lmayer@elgin.edu