Your readers often can figure out how much work you put into the essay by looking at your sources: (1) how many? (2) do you seem to understand what you read? (3) do you quote only the relevant passages? (4) do all your quotations come from the same page--or from throughout the book?
(1) Try to get one or two sources into each paragraph, either in the main text or in a footnote. In literature essays and essays that use historical documents or interviews, quoting the original words is essential.
(2) Normally it is not enough to insert a quotation; show evidence that you understand it. When the quotation includes words that exactly match the point that you are trying to prove with this evidence, you can get away with minimal or no analysis (in the example paragraph above, "hopefully" may be enough analysis of the quotation from Katherine's sister). Usually, however, a whole sentence (or two) of analysis should follow the quotation. Tell the reader why that quotation is important.
(3) Avoid long quotations. Make use of ellipsis (...) to omit parts of a quotation that are less relevant. Use brackets  to insert words that improve the flow of the quotation. You also can replace several words with your own paraphrase inside brackets, in order to cut down on the length of the quotation.
(4) When all your quotations come from the same page of a book, your reader might imagine that you did not actually read the whole book. Citing just one or two additional locations will put the reader more at ease.
In every case, it is essential to put quotation marks around the words you quote or to set off the material as a block quotation. Whenever possible you should include the exact page number. The reader should be able to find your source easily. If you choose to paraphrase rather than to quote, it is even more important to include the page number, which is the most efficient way to signal that the ideas have come from someone other than yourself.
Finally, follow the conventions in your field and in your class for proper citation of quotations within the text, in footnotes or endnotes, and in the bibliography or list of works cited.