This is essentially a response to Jackson's paper. Lewis makes the structure of the paper very explicit with his many titled sections and subsections. I'll simply suggest what are the most important parts for our purposes. Lewis offers many arguments and sometimes in a rather condensed style, so you may not have time to work through all of them carefully; if you don't, focus on the material suggested below (though you'll need to read most of the rest to get a sense of the context).

Lewis begins with some introductory examples and discussion (if you'd like non-phenomenal information about Vegemite and Marmite, try the websites vegemite.com and marmite.com). But he presents what he takes to be the import of Jackson's paper in the sections titled "The Hypothesis of Phenomenal Information" (pp. 284-286) and "The Knowledge Argument" (pp. 286-287). The full details of the unsimplified version of the knowledge argument Lewis presents on p. 287 are not crucial, but it will help in following his later discussion to think about the sort of possibilities he mentions when describing the weaker form of "Minimal Materialism" on pp. 286f.

Lewis's key argument against the hypothesis of phenomenal information is in the section "From Phenomenal to Epiphenomenal" (pp. 290-291) but the preceding section ("Curiouser and Curiouser," pp. 289f) is in part an introduction to it. It's OK to not to work through the extended argument that occupies the bulk of p. 291 but you should look at his statement of what he takes it to establish (the paragraph spanning pp. 290-291).

Lewis's final section ("The Ability Hypothesis," pp. 291-294) presents an alternative hypothesis. You should work through it carefully (I suspect you will find it easier going than some of the earlier parts of the paper) and we will spend a significant amount of time on it in class.