Why not start by visiting MethodBox
MethodBox aims to provide a simple, easy to use environment for browsing and sharing surveys, methods and data. Variables (ie columns in spreadsheet/csv data) can be searched for, metadata for the variables can be viewed and the variables themselves can be added to your cart and downloaded. MethodBox contains an internal web of data through users linking surveys, methods and people together. This enables more data re-use and the linking of communities of practice. MethodBox is a Ruby on Rails based web application that can be seeded with csv style datasets. It's original intention was to support health researchers involved in obesity data investigations with emphasis on datasets from the UK Data Archive. It is now opened up to the community at large and anyone can browse and find data. Registered users can add their own data and create and download data subsets.