For an LLb essay? So nothing to do with what law is in practice Just some reasoned ramblings through legal principle, history and theory then, as seen by academics LOL(Well,be fair, that's how the essays of some students always turned out!)
Constitutonal law books, as suggested, sound a good place to start.
It may be that the questioner also has in mind that there's a contrast between both statute law on the one hand and common law here on the other (both have pros and cons) and then again Codes as in , say, France.An allusion to Codes might be of interest in the context of how our law has developed and how that compares with the more rigid system of codes.Is it 'better'? Without knowing whether this aspect of legal theory has been taught in your course, it's hard to say
Sometimes comparisons are taught for the purpose of showing that ours is not the only, or best, way.Some people on this site (one anyway) had to learn Roman Law, as though knowing how to manumit (free) a slave or the procedure for marrying and divorcing a Roman citizen (one involving confarreatio, which had something to do with a cake) was a useful exercise.It could be, because Roman lawyers, particularly in sale of goods and contracts, saw legal problems differently from us, but not necessarily wrongly.