Windows 7 has support for burning ISOs built in. Just double-click on the ISO or right-click and choose "Open with" -> "Windows Disk Image Burner" if some other program is set to open ISOs by default. The image burning wizard will open. Select the drive to burn to, insert a disk, then click "burn".
To burn regular files to a disk, insert a disk, then go to the folder where your files are stored. Click "Burn" in the toolbar at the top of the window. Choose "with a CD/DVD player", then click "next". You can then drag-and-drop additional files into the window which opens, then click "burn to disc" once you're done copying over the files.