I recently received a DELL laptop (Precision M4700) with Windows 8 pre-installed. 
The first thing I did was trying to install Ubuntu 13.04. The installation succeeded, but there was no Grub or anything, just Windows 8.

After some research Boot-repair did the job and now I have a dual-boot with Windows 8 and Ubuntu 13.04. 
Pretty easy to do, in fact, if you know what to do:

1. Disable secure boot in your BIOS (press F2 when your computer starts to enter the BIOS)

2. Start Windows 8 and use the disk manager to decrease and create an empty partition (size at least 10 GB).
NB. You can also use a live-DVD but that takes some time to start...

3. Insert the Ubuntu live-DVD and restart your computer, enter the BIOS again and make sure it will first boot from your live-DVD and exit the BIOS.

4. Your PC will boot from the DVD, choose to install Ubuntu. Make sure you install it on the partition created at point 2 (choose: something else).

5. Restart/reboot, you will notice that nothing seems to have happened and that it will start Windows 8. No worries.

6. repeat step 3 and this time choose to Try Ubuntu

7. Once Ubuntu is started, install boot-repair:

open a terminal and enter: sudo add-apt-repository -y ppa:yannubuntu/boot-repair && sudo apt-get update

then enter: sudo apt-get install -y boot-repair && boot-repair

8. In boot repair open the advanced options and click on Apply

9. If you receive a message about a Buggy kernel, answer with Yes

10. Thats all. Reboot and you will see the Grub boot loader with an Ubuntu and a Windows 8 UEFI option.


Good luck!

Ps. Did some "time to start testing". How long does it take to start the OS and that I can use a browser from the moment I press enter in GRUB.

Windows 8: 55 seconds
Ubuntu: 10 seconds