John Donne is not an easy poet - in my first year of uni I could hardly understand him at all, and even now I find his intelligence and wit so bewildering at times that some of his poems are impossible to fully understand without the help of good annotations. The Oxford Student texts edition provides very good notes which certainly facilitate the general understanding of the meaning of Donne's poems (if only I knew about this edition during that first year of uni!). In addition, there is also an Approaches section which looks at the poems from a theme point of view, e.g. love and religion. The Approaches part offers a general discussion of the poems that fall under a specific theme and encourage independent study by asking questions about the reader's individual response, rather than assuming that Donne wrote the poems with just one interpretation in mind. Great help - if you you feel as if you don't fully understand Donne, do get this, it will clarify a lot of questions you might have.
I had forgotten how much I love Donne's poetry. This superb recording, by fine British actors including Nathaniel Parker and Jeremy Northam, reminded me forcefully. Beautifully read selections of a variety of the poet's finest works. Make sure you're sitting down when you listen to "To His Mistress..." or your knees may buckle under you. Highly recommended.