You will have to contact blue yonder and find out a few things -

How much space you have.

Does it have FTP access.

If so, the server address, your username, and password.

And you will also need to know the url of your space.

If it does have FTP access, then you can log into it using just a file browser in windows, but its a lot better to use an FTP client such as Cute FTP, or my personal favorite Flash FXP.