Yes, if you get inDesign CS5.5 and then install the free DPS tools, you'll be able to create folios and share them with anyone else who has an iPad through the free Adobe Content Viewer app. If you want to create your own viewer app (such as Newsweek or Vanity Fair), that's when you need to pay more money. One other bonus is that if you buy InDesign CS5.5 now, you can update to InDesign CS6 for free. But before you dive in, watch a few videos and learn the workflow basics. Here's one place to start:
2. You can distribute proof of concepts and test versions for free using the Adobe Content Viewer. No need to spend any money on that step.
Now is great time to upgrade. You’ll get 10% off the cost of CS5.5 (if you spend $375 or more) and you’ll also get a free upgrade to CS6 when it ships.
Hope that helps,