The first time you cite a source, it is almost always a good idea to mention its author(s), title, and genre (book, article, or web page, etc.).
If the source is central to your work, you may want to introduce it in a separate sentence or two, summarizing its importance and main ideas.
Whenever you change the original words of your source, you must indicate that you have done so.
Otherwise, you would be claiming the original author used words that he or she did not use. You could accidentally change the meaning of the quotation and falsely claim the author said something they did not.
For example, If you have already introduced the author and work from which you are citing, and you are obviously referring to the same work, you probably don't need to mention them again.
However, if you have cited other sources and then go back to one you had cited earlier, it is a good idea to mention at least the author's name again (and the work if you have referred to more than one by this author) to avoid confusion.
However, just skipping it would not work -- the final sentence would not make sense without it. In order to do so, you will need to use some editing symbols.
Your quotation might end up looking like this: In his essay, “United Shareholders of America,” Jacob Weisberg insists that “The citizen-investor serves his fellow citizens badly by his inclination to withdraw from the community. by focusing his pursuit of happiness on something that very seldom makes people happy in the way they expect it to.” The brackets around the word [money] indicate that you have substituted that word for other words the author used.
In this case, however, the paragraph following the one quoted explains that the author is referring to money, so it is okay.
As a general rule, it is okay to make minor grammatical and stylistic changes to make the quoted material fit in your paper, but it is not okay to significantly alter the structure of the material or its content.