Download from the following:http://www.linuxmint.com/mirrors.php?id=23
This will get the KDE DVD with more useful programs and will give you an environment that is very similar to where your starting from.
Don't follow that links instructions just yet.
Try the live DVD out for a while to be sure you want to do an install dual boot or otherwise.
Download the ISO also known as an image, and then use your favorite program to burn it to DVD that could be Roxio, Nero, Sonic or ImgBurn.
Leave the DVD in, and do a reboot on your system. You may have to go into the BIOS to activate DVD/CD booting in the options. You can get to the BIOS by either the F2 or DEL key during boot up on most current PC's. Its one or the other.
Give the Live DVD a whirl for a while then do an install.
No need to worry about making a bootable disc, the image has all that done for you.