For some of the following, I have indicated difficulty: "basic" - easy to read references, explaining basic ideas. If you are having difficulty with the reading you do for lecture, you may want to choose these "intermediate" - similar to your assigned reading in difficulty. "advanced" - more difficult than your text, you should have a grasp of the current material (and some biochemistry from Cells last semester) to be able to follow; don't get overwelmed: keep in mind what information you are looking for.