So here are the simple steps to get your own Puppy OS. You might want to read this review of Puppy Linux here.
Download Puppy: You should download the latest version of Puppy from here.
Burn A CD: Using any CD burning program you like, burn the downloaded .iso file to an CD. Preferably a shiny new CD. A DVD would work fine too.
Reboot: With the CD inside the CD drive restart the PC. If your BIOS settings are properly configured, your PC would boot into Puppy Linux. If your PC isn't configured to boot from CD and you end up booting in your Ubuntu, follow the simple tips given here.
Select Proper Configurations: While booting in Puppy will ask you few question. Nothing difficult, just select the appropriate settings such as keyboard and video card. In case of selecting video card, if your PC is relatively modern go for Xorg or else if that doesn't work opt for Xvesa. You can preview the changes which will happen.
Try out Puppy: Before you install Puppy, I would suggest you to stop and take a look around, get a feel of the OS before you install it.
Installation: All the steps from now on are related to installing Puppy.
1. Goto Menu > Setup > Puppy Universal Installer.
2. Select the appropriate drive. If it is relatively modern go for Internal (IDE or SATA) option if your PC is very old select the Ancient True SCSI option and likewise for other hard drives.
3. Choose which physical hard drive you want to install to.
4. Choose which partition you want to install Puppy onto. If you are unsure about it, don't worry even if you choose the wrong drive you can uninstall Puppy by simply deleting the Puppy folder. You can try later.
5. Sanity Check: Read the things given, if they don't make sense to you, hit continue.
6. Hit OK.
7. Select CD.
8. Choose 'Frugal'. With Frugal install you don't run the risk of losing any data. Puppy won't format your drive and will coexist peacefully with your primary OS.
9. Give any name you want. I have named the folder 'Puppy'.
10. Wait...
11. *Important*:
In order to save hassles later on do this. Goto Menu > Graphics > mt-Paint Snapshot Screencapture.
Take a screenshot of the following window.
12. Okay.
13. *VERY Important*
Now navigate to the /tmp folder. Look for a file named NEWGRUBTEXT.
Use the file manager for this. Keep this window open. Now click on any one of the several drive icons displayed at the bottom row of the desktop. Now drag the NEWGRUBTEXT file from the tmp folder to the selected drive. Select 'Copy' in the pop-up menu.
14. Restart: Reboot into Ubuntu this time.
15. Terminal: Fire up a terminal, now type these commands in it:
sudo cp boot/grub/menu.lst /boot/grub/menu.backup
This is to backup your Grub, incase you muck things up.
gksudo gedit /boot/grub/menu.lst
This will open up the Grub bootloader in Gedit.
If you are on KDE use this command:
kdesu kate /boot/grub/menu.lst
If nothing happens navigate to the folder File System > Boot > Grub
Open the file menu.lst.
16. Navigate to the bottom line.
17. Read the step 13. Now go to the folder where you dropped NEWGRUBTEXT and open it.
You will find some text like this:
title Puppy Linux 410 frugal
rootnoverify (hd1,0)
kernel /Puppy/vmlinuz pmedia=atahd psubdir=Puppy nosmp
initrd /Puppy/initrd.gz
18. Copy all of it and paste it in the menu.lst file.
19. Hit save to make the changes.
20. That's it! You have successfully installed Puppy alongside Ubuntu.