Encyclopedias and dictionaries can be good starting points for your research. Frequently, encyclopedias provide summaries of topics along with valuable bibliographies to lead you in the direction of more reading on your subject.

Blackwell reference online

Cassell's queer companion: a dictionary of lesbian and gay life and culture - SML, Starr Main Reading Room, HQ76.25 S74 1994

Encyclopedia of contemporary LGBTQ literature of the United States - SML, PS153.S39 E53X 2009

Encyclopedia of gay and lesbian popular culture - SML, Starr Main Reading Room, HQ75.13 .P76X 2008

Encyclopedia of lesbian, gay, bisexual and transgender history - SML, Starr Main Reading Room, HQ76.3 U5 E53X 2003 +(Oversize) or available online

Fantabulosa: a dictionary of Polari and gay slang - SML, Starr Main Reading Room, PE3727 G39 B34 2002

Gay histories and cultures: an encyclopedia - SML, Starr Main Reading Room, HQ75.13 G37X 2000

Gay life and culture: a world history - SML, HQ76.96 G395 2006

Historical dictionary of homosexuality - SML, Starr Main Reading Room, HQ75.13 P53X 2009

Lesbian histories and culture: an encyclopedia - SML, Starr Main Reading Room, HQ75.5 L4395 2000 or available online through Orbis

LGBT America Today - SML, Starr Main Reading Room, HQ73.3.U6 L43X 2009, volume 1-3

Outbursts!: a queer erotic thesaurus

Routledge international encyclopedia of queer culture - SML, Starr Main Reading Room, HQ76.96 R68 2006