Ok, first for the AHCI mode - this is a storage mode you want to use as it provides better performance for SSDs.
To enable it you need to go into your BIOS.
Then select "Settings", then "Advanced", then "Integrated Peripherals". Then look for "SATA Configuration" and for the "SATA mode" make sure it is set to "AHCI", not "IDE".
While you are in the BIOS make sure you set the primary boot device temporarily to the DVD drive (so you can install windows fresh onto the SSD). To do this, go back to the "settings" part and select "boot". Then make sure the "1st boot" is your particular DVD drive. When you have installed windows and updated the SSD firmware I would recommend you change the boot order again - so the SSD is the primary device. This helps as it will prevent disks trying to boot when you don't want them too and should also speed up your boot slightly.
As for updating the firmware on your SSD, first check what it comes with as default. If it is "0309" or "000F" then I would leave it as it is, but if it is "0001", "0002" or "0009" then I would update. How to do this is explained very well
here (select the "crucial m4 2.5in SSD") in the "
guide" link.
Basically you copy the application onto a bootable CD/DVD, ensure the SSD is plugged into one of the first SATA ports, boot into the application (as you will have already set the DVD drive to be the first boot drive), say "yes" and it automatically updates the firmware for you.