Tools for documenting your data work
Documenting the transformations you perform on your data can be as simple as a detailed prose explanation and a series of spreadsheets that represent key, intermediate steps. But there are also a few products out there that are specifically geared towards helping you do this. Socrata is one platform that helps you perform transforms on spreadsheet-like data and share them with others easily. You can also use the Data Hub (pictured below), an open source platform that allows for several versions of a spreadsheet to be collected together into one dataset, and also auto-generates an API to boot.
If you want to get really smart, you may like to try using version control for your data work. Using version control will track every change made to the data, and allow you to easily roll back if there are any mistakes. Software Carpentry offer a good introduction to the topic.

