One of the benefits of having a deep-dive data portal is that you can connect your data together and enrich your data pages
The CONSTRUCT form of SPARQL is a really useful when working with large RDF datasets as it makes it easy to pull out a small graph that you can then work on locally. This post goes through the basics of using SPARQL CONSTRUCT and shows some "stupid SPARQL tricks" you can achieve with CONSTRUCT.
Most of the data that organisations hold will be in some form of flat data, either in spreadsheets or relational databases. In order for the data to achieve either 4 or 5 star levels of Open Data, this data must be changed to not only use non-proprietary formats but it must also use URIs so that each object can be linked with other data across the World Wide Web.