In the main menu click Create and then Meal Plan to create a new meal plan. Fill out the Name (as it's required) and any other details you wish to include and then click Save in the bar at the bottom. After the meal plan is created, you can change any of these settings by going back into the "Details" tab.
Now that you have specified the plan details, you can move on to scheduling recipes into the plan.
At any point you can preview how other users see your plan by going to the "Preview" tab.
If you want to share your meal plan you can do so publicly with the social sharing icons along the right or you can use the "Share ..." button to share with particular clients.
If you'd like to target particular nutritional goals then you should find the Dietary Goals feature very useful. You can add a series of goals as shown below and then be able to see instantly where your meal plan is falling short:
When on the "Meals" tab you can see nutritional stats on the far right and any stats that don't meet the goals set will be in red: