Much has been written about the nature and use of Story Point assignment in terms of development estimation for User Stories, but rarely can one find a defined scale which is used on a practical basis; here you have just such a scale and definitions which Minerva Group scrum teams use as a basis of their Story Point estimations.
Minerva Group has developed an Excel spreadsheet tool to help business Product Owners define, organize, and visualize the relative value of their software engineering efforts.
All instructions for use are contained on the first page. The tool may be downloaded here.
The scrum / sprint cycle works exceptionally well for functional software development but does not lend itself well to two other important project considerations, namely i) graphic design & layout and ii) initial production environment implementation. This article discusses why and suggests approaches to handle them appropriately around the scrum context.