Head on over to the Wikipedia and you’ll find that there is developing a very useful corpus of entries on UK law.
The United Kingdom Law page indicates the scope of the contributions thus far, though you’ll find the structure predictably chaotic.
However, there are some more structured starting points – list maniacs are at work. There is a comprehensive List of Acts of Parliament of the United Kingdom Parliament from the year dot (1707), also ASPs and ANIPs and pre-UK Enlish, Scottish and Irish Acts. There are also lists of SIs from 1948.
All the Act entries are linked, though red links lead to the “Article not found” page. Links in blue are to articles that do exist – and there are a fair number, though of course variable in quality. See, for example, the article on the Gambling Act 2005.
The lists were created by one David Newton whose main passion is lists of things military.
There is also a List of House of Lords cases (from 1997) started by Samuel Buca, a final year law student.
Articles on cases are scattered around the Wikipedia. One useful list is of Landmark decisions, with a UK section. User BD2412 seems to have started this. His profile led me to the Wikipedia:WikiProject Law page. This Wikiproject is aimed at creating a greater consistency among the law related articles. Key areas of concern include consistency in defining concepts across multiple jurisdictions and proper categorization of articles.
So I revisited two independent UK law wiki projects: WikiCrimeLine and Wiki Mental Health. They both seem to be growing and developing apace, but is there scope for these projects to feed off the Wikipedia and vice versa? I don’t know enough about the mechanics of it, but would be interested to learn.