Helpful setup links:
http://www.toddklindt.com/blog/Lists/Posts/Post.aspx?ID=303
http://heidibrebels.be/blog/archives/2011/office-web-apps-error-sharepoint
Other Helpful Info:
-Default web app pool that you create service applications in (default SharePoint app pool) has to have access to content database.
-WebApps won't open xls (excel) extention documents only xlsx...will open xls in Excel Client
