This has been asked before, but unfortunately I haven’t figured out an easy way to do this. So far you can have multiple pages based on each category….or all categories on the same page, but I haven’t seen an easy way to reorganize those on the same page. There is however a plugin called Post Types Order – http://wordpress.org/extend/plugins/post-types-order/ which allows you to organize each post order manually by drag and drop interface…….but this will effect your blog post order as well (I think, I could be wrong). So if you don’t really have a blog, then the solution would probably be the suggested plugin.
Here are some of the other tutorials I created for the Portfolio so far – https://appfinite.com/tutorials/