You can upload your files using FTP, Microsoft Frontpage, or any other software that is compatible with one or the other of those protocols.

FTP:
After logging in, you will see a folder named in the format 'domain.com' with the same domain name as your web site.  Be sure to switch directories into this folder before uploading your files, as that folder itself is your web root, NOT the folder you are in when you first log in with FTP.

FrontPage:
You can connect with FrontPage directly to the URL of your site, or the temporary URL (see related articles).  Once logged in, you are already in the correct location to copy your files and do not need to switch directories first.

Both Methods:
After reaching the correct location, you will want to delete the 'index.html' file that is in place in your web root.  Another copy of the same file can be found at 'login.html' if you need it later.  This file contains logon forms for your control panel and site builder.  Depending on the name of your default file, you may need to make changes to your default document configuration (see related articles).