0.
These instructions are for Ubuntu.  If you want to run Ubuntu as a virtual machine on your computer, check out:
VMWare Player (PC, free): https://my.vmware.com/web/vmware/free#desktop_end_user_computing/vmware_player/6_0
Virtual Box (PC, free): http://www.oracle.com/technetwork/server-storage/virtualbox/downloads/index.html
Parallels (Mac, unsure?): http://www.parallels.com/

Once you have Ubuntu running, execute the following sequence of commands from the command line.

1. 
sudo apt-get install qemu qemu-system qemu-user qemu-utils

2. 
wget https://launchpad.net/gcc-arm-embedded/4.7/4.7-2013-q3-update/+download/gcc-arm-none-eabi-4_7-2013q3-20130916-linux.tar.bz2
tar xjvf gcc-arm-none-eabi-4_7-2013q3-20130916-linux.tar.bz2
sudo mv gcc-arm-none-eabi-4_7-2013q3 /opt/ARM
echo "PATH=$PATH:/opt/ARM/bin" >> /home/"$(whoami)"/.bashrc
source /home/"$(whoami)"/.bashrc
arm-none-eabi-gcc --version

3. 
wget http://www.taylortjohnson.com/class/cse2312/f14/hw/hw05.tar
tar xvf hw05.tar
make

4.
qemu-system-arm -s -M versatilepb -daemonize -m 128M -d in_asm,cpu,exec -kernel hw05.bin

This should open a QEMU console window.  Once started, press ctrl+alt+3 to change to QEMU's UART display output, it should be printing 0 through 7 repeatedly.

use -S to start paused

5. with gdb
qemu-system-arm -s -M versatilepb -daemonize -m 128M -d in_asm,cpu,exec -kernel hw05.bin
gdb-multiarch

target remote :1234
set architecture arm
symbol-file hw05.elf

You can use GDB to look at memory values of particular addresses, register values, etc.  See the file hellow_world.gdb for a basic GDB script file.

