Write an article based on this "Log into Gmail. Compose an email. Attach your desired file to the email. Save or send the email."
If you've never used it before, you will have to set up an account. Use the red Compose button toward the top left-hand corner of the page. Click the Attach button, locate the file, hit Open, and wait for it to load. You can either save the email as a draft so that you can access it in your drafts folder whenever you need it or send it to yourself so that it goes to your inbox. Be sure to give your email a subject so that your file is easy to find.