Yes there are many versions, old & new. The latest version is CS2. I'm sure if u want to buy, it must be the latest version, right? U could have found out easily which is the latest version by searching on yahoo
Unless what u mean is "which photo editing software do u people recommend?". If that is what u mean, then it's a completely different story
If you are not really that much of a hardcore post processor you can try photoshop elements as it has most of what you might need. If you are feeling adventurous try downloading GIMP (search for gimp.org) its similar to photoshop but completely free.