can find you links to information on how to create a genogram and some links to download trial versions of some genogram software to make some simple genograms. however, you have to put the work into it.
my niece has been involved in doing a genealogy of the family for several years and has another software program. her genealogy runs hundreds of pages. for the assignment you are doing, i don't think you need that. you could actually create a genogram using the symbols on the drawing toolbar of word as well as the various lines and arrows that are there to connect them. all you need to know is what the symbols need to look like and how to make the connections. if you have powerpoint software and the right powerpoint template for it, you can create a genogram on powerpoint as well. if you are having to create this for a school assignment, ask your instructors if there is software in the school computers that you can use to create the genogram.
the computers at my cc have microsoft visio installed in them and we used that software to create organizational charts. i imagine you can also use visio to create a genogram, but you may also need to have excel installed as well since we used excel to help create the linkages in our organization charts with visio. i believe you can download a trial version of visio from the microsoft office web site.
another software i seen mentioned on allnurses that students have used for creating care maps, which can look similar to a genogram in some ways, is inspiration. http://www.inspiration.com/
you can download a free trial of the software from the site.