Understanding order of processing and scope of calculations

I don't have a solid understanding of where in the stack and when in the order of processing of "things" within XRM:

1. Calculated field on entity
2. Business Rule on field (from Field properties view)
3. Business Rule on Form (from Form Editor )
4. Business Rule from Entity (in Solution Explorer tree view)
5. Workflow
   
   1. Real-time
      
      1. Scope (Organization, Entity)
      2. Created (Before|After)
         
         1. Before is before commit to database
         2. After is after commit to database
      3. Record Fields Change
      4. Deleted (Before|After)
   2. Background
      
      1. Created (Before|After)
      2. Records Fields Change
      3. Deleted (Before|After

Are there any resources I can study to help ground my understanding?

What I'm trying to accomplish is setting the value of a field:

A Customer is related to a Case.  A Case is related to an Assessment.  The field exists on the Assessment and is calculated based on a value on the Customer record. 

How would I accomplish this?  All fields and BRs are limited to the current entity.

Thanks!