One extremely useful resource for undergraduate students is the student section of the APA website (http://www.apa.org/students/). It is a good idea to join APA as a student member (the fee is about $25.00), which gains you access to some of the content that is most useful for applying to graduate school.
Another wonderful resource is the edited book published by APA, "Getting In: A Step-by-Step Plan for Gaining Admission to Graduate School in Psychology, Second Edition" (http://books.apa.org/books.cfm?id=4313012). This book is highly recommended for anyone who plans to apply to graduate school in psychology. APA's description of the book is quite accurate and worth repeating here:
Getting In, Second Edition is an update of the American Psychological Association's essential resource for anyone considering graduate study in psychology. This handy, readable book simplifies the process for applicants and increases their chances of being accepted. Useful timelines, tips, and tools break the tasks into manageable steps and help readers define their goals, select programs, and navigate the application process. A monthly timetable and detailed worksheets for selecting the best program matches are included, and a resource section provides a list of publications and organizations that are useful in the various phases of applying.
Readers will learn what criteria admissions committees use to evaluate applicants, how to improve their qualifications, and how to showcase their talents in personal essays, letters of recommendations, and pre-selection interviews. The costs of a graduate education and financial aid information specific to graduate students are also discussed.
Members of special populations, such as women, ethnic minorities, gay and lesbian applicants, and applicants with disabilities will find resources and guidance particular to their needs.
While applying to graduate school can be challenging, this book demystifies the process and allays students' concerns about how to tackle it.
The LU Career Center has critically important books and other resources you will need to research psychology graduate programs, such as APA's "Graduate Study in Psychology" (published annually, providing information about all graduate programs in psychology). Information about GRE testing, the Subject Test in Psychology, Internships, and much more also are available at the Career Center. In addition to these resources, make sure to get to know Kathy Heinzen, Director of the Career Center, who has a wealth of information about the graduate school application process.
The faculty members in the psychology department (http://www.lawrence.edu/dept/psychology/faculty.shtml) represent all of the major areas of specialization in the field. They are more than happy to help you in any way they can as you go through the process of learning about graduate school. It is best to get started early, working with faculty on the things you can be doing early in your Lawrence career (e.g., research, internships, etc.) in order to strengthen your resume as you proceed through your career at Lawrence.