Fonts in Puppy Linux are stored in files with the extension ttf. If you have some .ttf files you can add them in:
Open Office can use these new fonts immediatly without rebooting the machine. For example, you would like to add the Windows fonts (such as Times New Roman). To do this just copy the fonts that are located in C:/WINDOWS/Fonts. For a frugal install that means that you can find the Windows fonts in /mnt/home/WINDOWS/Fonts.