If it's CourseInfo.
logon to your course and go to the Tools|Digital Drop Box and select Send File. Name what you're going to send. Browse to the document (probably on the desktop), select Open.

Now submit the file. You should see a confirmation of your submission.

If it's FirstClass.

logon to FirstClass and go to the Conferences|Classes|Language (e.g. SPAN, ASL, JAPN, etc.) Folder. Double click the language and then your class and section. E.g. SPAN101-01.

Now compose a message to the course InBox (Hint: If you have selected the course inbox and then create a new message, it will auto-address to that conference location!). Attach your file and send.