In a nutshell: Shop'NCook Menu has a meal planner, Shop'NCook Home doesn't.
The meal planner of Shop'NCook Menu consists of a calendar where you can plan your menus in advance. It also computes the nutritional analysis of the menu and creates the shopping lists based on your meal plans.
Shop'NCook Menu also has the ability to create shopping lists for several shops and to synchronize your recipes between several computers. ShopNCook Home only supports one supermarket and doesn't have synchronization functions.
See the more detailed comparison between the Shop'NCook versions.
You can at any time upgrade from Shop'NCook Home to Shop'NCook Menu for the price difference between the two editions.