For sending large files, like audio files, I have been using sendthisfile.com. You can use it free or get the more advanced service. I used it free for a while, but it uploads faster when using the pay service, so I bought the minimal service for sending data. So far that has been enough, but I am trying to decide if I will eventually need more. Anyway, the link is below, in case you need something like this.
I like YouSendIt-dot-com the best for my file transfers.
It is free for files up to 100 MB. For 10 bucks a month, you are allowed 2GB of audio files every month. For $30 a month, which is a good feature for companies, you can put your own logo on all transmissions. Here's the link: Compare Prices at YouSendIt-dot-com
Then you click the button called BROWSE. When you click BROWSE, a dropdown window will appear. You would then locate the file you want to send, just like you would an e-mail attachment.
You can write a brief message in the MESSAGE area, but you don't have to write a message if you don't want to.
Then you would hit the SEND THIS FILE button, located on the bottom.
It takes longer to upload than download, and so, depending on how large the file is and what kind of Internet connection you have, that will determine how long it will take to send. Downloading, though, goes much quicker than uploading.
It's a piece of cake after you do it a few times. :-)