If you're considering writing about A Modest Proposal you do need to have some background sense of what satire is, its origins, and the context for Swift's writing. Try listening to : this programme about Roman satire from 'In Our Time'--which as a resource is invaluable. A great way to educate yourself about the arts is just to browse through these programmes where cultural issues are discussed by a team of experts.
Think also about using the BBC history site to give you some sense of historical context and background. For instance, look at this crystal-clear article on The Glorious Revolution by Dr Edward Vallance
Another extremely useful site is The Victorian Web. This invaluable resource gives reliable background information and critical reading for many key texts that we'll look at this year. Look at their take on the Glorious revolution here, for instance.
For even better detail about specific authors go to the author pages on the Victorian Web. Here, you can find all about Swift, even though strictly speaking he isn't a Victorian, with links for his biography and literary context as well.