Hello,
you'll need SAP Service Marketplace (SMP) credentials to download the software. You don't need a license to get IdM up and running but you'll need a license to run AS Java. (SAP differs from American software companies in not offering trials or developer versions.)
Documentation is available in the documentation link in the left navigation pane or: http://wiki.sdn.sap.com/wiki/display/Security/Planning+%28Release+7.2%29
regards, Tero