I noticed that the Marketo University has added new courses on the ever complex RCE and RCA modules. I went through it and it is a good update to the old docs, most of which are no longer available. Here are some of the links.
Learning RCE is easiest when you use it everyday and rely on the reports to deliver actionable information. I've learned a ton by using it the past few months, including insight into why Marketo itself is setup a certain way. Even if you do not have RCE, there are several videos, including the Setup videos which will help you understand Programs more deeply. The earlier you start using Programs properly, the more you can have reliable reports from RCE later.
**Please keep in mind that some courses may incur a fee, which may depend on your company's contract with Marketo.