An important preparatory step in approaching any upgrade is to verify that your software stack is certified with your database, your new database version is certified on your hardware/OS platform, and so on. The Certify interface on My Oracle Support was originally pretty difficult to use, but we’ve now just seen the second round of major enhancements. Here’s a screenshot:
Try the interface, and let us know what you think. There is a feedback link at the bottom of the Certify page.