These are a couple of good web sources for profiles.
These books have profiles — sometimes very detailed profiles — of both past and present U.S. Supreme Court Justices.
Biographical Encyclopedia of the Supreme Court: The Lives and Legal Philosophies of the Justices (2006) by 
The Justices of the United States Supreme Court, Their Lives and Major Opinions (1995) by The Supreme Court Justices: Illustrated Biographies, 1789-1995 by To find full-length biographies of Supreme Court Justices, use this form to search Ignacio, the USF libraries' catalog.
Use a "Subject" search, and enter the justice's name, last name first, as in this example:
Rehnquist, William
An effective and efficient way to find articles about justices (as opposed to articles that merely mention justices) is to use Index to Legal Periodicals. For more on finding articles, see the Zief Library's Finding Articles research guide.
To find articles about a justice, use the Advanced Search option, enter the justice's name in the top search text box, and select "SU Subject Terms" from the adjacent pull-down menu. If using both first and last name, put the last name first, as in these examples:
white, edward
white, byron
For articles written before 1908, search Index to Legal Periodicals in print (K 33 .I54 Law Reference). Look for the justice's name under the subject heading "Biography: individual."
HeinOnline's History of Supreme Court Nominations library is the best place to start when you want to see a justice's nomination hearing transcripts (and related information). The government's free FDSys source is a good alternative for transcripts of more recent hearings.