I have a netbook that I want to install Ubuntu onto. I do have a good Mac computer that I can make a bootable USB drive from, but I'm confused on how to go about making it.
In order to make an Ubuntu live USB with persistent file storage, use UNetbootin (Windows<=Windows 7/Mac/Linux/Ubuntu Software Center). The flash drive you use should be at least 1GB in size (2GB or larger for Ubuntu 14.04 and onward) and formatted to FAT32. Add to that whatever space on the flash drive that you want to use for persistent file storage. UNetbootin will automatically format the USB flash drive to FAT32 if it is not already formatted to FAT32. In either case the formatting procedure will delete all of the files that are already on the flash drive.
It is very important to verify that the device that you are installing the Ubuntu live USB to is indeed your flash drive, so that you don't overwrite any of your system or personal files which may make your operating system unbootable. In Ubuntu you can find the device name of the flash drive using Disks application. In the picture below the name of the flash drive is
In the picture below a 1GB persistent file storage space has been created by selecting 1024 MB next to where it says: Space used to preserve files across reboots.
In order to enable your computer to boot from the USB flash drive, you must enter your BIOS menu by pressing one of these keys: usually either Delete, F2 or F10 as soon as the motherboard splash screen appears when the computer is booting. In the BIOS menu, you need to change the boot order so that the USB flash drive, which is usually called USB-HDD in newer computers, is the first entry in the boot sequence, and then save your new BIOS settings and exit the BIOS setup.
there's a software called UNEBOOTIN (http://unetbootin.sourceforge.net/), it will let you create a bootable USB disk, just follow the instructions on their webpage