How to setup a good workflow?

How to setup a good workflow?

Ok, we made a new module "Repair" ... works fine. We add a macro 1. Send email to customer " We received your repair at our shop..."  2. Set reminder.... 7 days later.

Now, I have a open task. Perfekt. Due Date, Subject, Priorty, Status, Realted to, Lead Contact. First of all, where I can change this related list? 

What I really need is to know is what is my next step within the related list? In this case after 7 days - we have to do a "check repair status".  What I need:

Due Date, Subject, - next step here.....check repair status-, Priorty, Lead Contact

How to do that?

Thanks