Boxes and Arrows: An introduction to user journeys might be a good read for you:
Creating a user journey places a strong emphasis on personas and also merges the creation of scenarios and user flows. However, unlike user flows, hierarchies, or functional specs (which explain the interaction between a user and a system’s logic and processes), user journeys explore a user’s mental and lived “patterns, processes, and paths” and translate these into web-based experiences.
Think about the user’s needs and the associated content in some form of time-based progression. You need a beginning, middle, and end. It is all rather logical; the trick is simply to role-play. Put yourself in the mindset of your user and imagine how the need states shift as you move through the overall process.
In other words, a scenario can be thought of as a singular situation and a journey can be a collection of scenarios that together form a narrative that defines the users total experience using your site.