Currently in my workplace we use Redmine as our backlog management system. It works pretty well for us, but lately (as the company grew), I've been noticing that our tickets tend to be very long (both in regards of the description text and the implementation effort). For what I understand, I think we're having a confusion between a ticket and a user story.

I'm looking for some documentation to guide me in how to manage the transformation of requirements gathering into actual "work orders" to pass to my team. Thanks!