This is an excellent collection of articles from the BBC outlining a wide range of issues surrounding the impending referendum on Scottish Referendum. In terms of the UK Constitution, this could be a useful example of the impact of devolution. With George Osbourne saying that a newly independent Scotland could not guarantee use of the pound, and Scottish Life saying it would quit Scotland for England unless and monetary and tax deal was struck, the debate is heating up. You should definitely keep up to date with this page.
On a related note, you should shy away from using it as an example of referenda for two reasons – 1. it hasn’t happened yet (AV or Wales 2011 would be better) and 2. it could be argued that this is, in fact, a plebiscite (GCSE historians should have echoes of the Saarland in their minds!)