Welcome Sounder! Nice scope you have on order, a lot of the members around here have the same scope and they'll all swear by it. With regards to software, it depends on what you are after - a planeterium, guiding software, image editing (for astrophotography)? There are heaps to choose from, just tell us what your needs are, we'll be happy to help.
But I would say there isn't really anything essential software wise that you would need starting out. These things I consider as "upgrades". You just need a good star map, some patience and a passion for the stars.