For an overview of the ways to cite electronic information in text in APA style, see the Purdue OWL, which provides an overview of the basic in text citation formats.
The APA Style website provides an overview of information regarding citations in text of electronic material on the APA Frequently Asked Questions page, including e-mail communications, entire websites, web pages with no authors, and website material with no author, no year, and no page numbers.
For complete information on citing references in text, see Chapter 6 of your APA manual. Note, specifically, the instructions on direct quotations, paraphrasing and acknowledging another author, as this determines how the in-text citation is formatted.
Table 6.1, "Basic Citation Styles" (on p. 177 of the APA Manual) shows how to do in-text citations based on the number of authors in the work being cited.
"Each reference cited in text must appear in the reference list, and each entry in the reference list must be cited in text. Make certain that each source refrenced appears in both places and that the text citation and reference list entry are identical in spelling of author names and year" (Publication Manual of the APA, p. 174).
If the name of the author appears as part of the narrative, as in the first example, cite only the year of the publication in parentheses. Otherwise, place both the name and the year, separated by a comma, in parentheses (as in the second example).
When a work has two authors, cite both names everytime the reference occurs in the text; use the ampersand (&) between names. When a work has three, four, or five authors, cite all the authors the first time the reference occurs; in subsequent citations, include only the surname of the first author followed by et al. (not italicized and with a period after al) and the year if it is the first citation of the reference within a paragraph.
Harris et al. (2004) argued............
Six or More Authors: Use the first author's name followed by et al.
No Author identified: Cte in text the first few words of the reference list entrh (usually the title) and the year. Use double quotation marks around the title of an article, a chapter or a web page and italicize the title of a periodical, a book, a brochure or a report (p. 176 of the APA Manual).
Corporate Author identified: Groups that serve as authors (corporations, associations, government agencies, etc.) are spelled out the first time they appear. They may be abbreviated in subsequent in-text citations IF the name is long and cumbersome and if the abbreviation if familiar (p. 176 of the APA Manual).
Include the specific page citation or paragraph number when using a direct quote (with quotation marks). See Section 6.03-6.08 for specific details.
(Jones, Harriett, 2008, p. 12)
(Shimamura, 1989, Chapter 3)