Plan B: Use Plan B if you have only a few, larger similarities or differences. After your introduction, in the next paragraph discuss one similarity or difference in BOTH works or characters, and then move on in the next paragraph to the second similarity or difference in both, then the third, and so forth, until you're done. If you are doing both similarities and differences, juggle them on scrap paper so that in each part you put the less important first ("X and Y are both alike in their social positions . ."), followed by the more important ("but X is much more aware of the dangers of his position than is Y"). In this format, the comparing or contrasting goes on in EACH of the middle parts.
Like with all essay outlines, informative essay outlines too should have a word count limit. Else they would defeat the very purpose of writing them. A good assumption is to use the one tenth fractions wherein the word count of an outline should be one tenth of the actual essay word count. By doing this you ensure that the main essay word count does not increase and at the same time the essay contains relevant and precise information. Depending upon the complexity of the essay you may wish to increase or decrease the word count of the outline. Some templates contain word count limits on the outlines and the essays.