How do I set up a permanode and what size of storage would be needed? What are the recommended hardware requirements?
As of now (November 2017) there is no "finished" software available that can just be installed and run as a permanode.
People who currently need a permanode (I think some block explorers have that) will have to collect databases from the latest milestones before each Snapshot (I think links some of them are shared on the Slack) and manually import them into an isolated node that is patched to not broadcast anything and to act as read-only.
As I don't have all of these databases, I don't know their exact size, but I believe each one is below 5GB, so in total less than 50GB (I am not here since the beginning, but I think there have been less than 10 snapshots so far).