Do you have any links to sources? This is going to be an issue for members of my family in a few years, I'd like to keep up on things.
Sure thing.
Cameron and Cameron was one of the first studies.
Cameron P, Cameron K. Children of homosexual parents report childhood difficulties. Psychol Rep. 2002 Feb;90(1):71-82.
Timothy Daley wrote a slightly outdated but excellent review on refuting pro-gay arguements and the early evidence of harm in gay parenting at:
http://www.frc.org/get.cfm?i=IS01J3
Stacey and Biblarz have made a bit of a stir in the news challenging the "no effect" bull even though as good liberals they favour homosexual parent "rights": Fox News article
That will do for a start. Bear in mind that of the last 49 studies in favour of homosexual parenting, 48 were published by those in activist groups that support homosexual parenting "rights" (Nidal).