I have assembled a few resources for Scouters with questions about sexual orientation and the pending membership policy change:

The American Psychological Association provides an excellent resource on the subject of sexual attraction in it’s  publication:
Answers to Your Questions For a Better Understanding of Sexual Orientation & Homosexuality 

There is no consensus among scientists about the exact reasons that an individual develops a heterosexual, bisexual, gay, or lesbian orientation. Although much research has examined the possible genetic, hormonal, developmental, social, and cultural influences on sexual orientation, no findings have emerged that permit scientists to conclude that sexual orientation is determined by any particular factor or factors.

Heterosexual people who wish to help reduce prejudice and discrimination can examine their own response to antigay stereotypes and prejudice.

Studies of prejudice, including prejudice against gay people, consistently show that prejudice declines when members of the majority group interact with members of a minority group.

The DOD’s stance on the issue helps answer  the question of separate facilities or standards for gay Scouts and leaders.

From the Department of Defense Repeal of ‘Don’t ask Don’t Tell’ (DADT): Quick Reference Guide

STANDARDS OF CONDUCT
Existing standards of conduct continue to apply to all Service members regardless of sexual orientation. All Service members are responsible for upholding and maintaining the high standards of the U.S. military at all times and in all places.
MORAL AND RELIGIOUS CONCERNS
There are no changes regarding Service members’ exercise of religious beliefs, nor are there any changes to policies concerning the Chaplain Corps of the Military Departments and their duties. The Chaplain Corps’ First Amendment freedoms and their duty to care for all have not changed. All Service members will continue to serve with others who may hold different views and beliefs, and they will be expected to treat everyone with respect.
PERSONAL PRIVACY
The creation of separate bathroom facilities or living quarters based on sexual orientation is prohibited, and Commanders may not establish practices that physically segregate Service members according to sexual orientation. Consistent with current policy, Commanders will continue to maintain the discretion to alter berthing or billeting assignments in accordance with Service policy in the interest of maintaining morale, good order and discipline, consistent with performance of the mission.

Scouts UK has had no ban for many years now – Resources from Scouts UK
Supporting a Young Person who is Gay and in Scouting
Being Gay with and Adult Role in Scouting
It’s OK to be gay and a Scout! Advice for young people

A reply to the often stated argument against inclusion that Scout’s Canada lost 50% of it’s membership after adopting an inclusive policy:

“The author indicates that Scouts Canada lost 50% of its membership once the organization was “forced” to admit gay members. This is incorrect.Scouts Canada peaked in membership in the mid-sixties and went through a long period of steady decline.

We’ve invested a tremendous effort in strengthening our organization, and are proud of the fact that we’ve experienced four straight years of growth – it’s the first time that’s happened since 1975.

There are multiple factors for the drop in membership: The increased number of leisure and athletic options for youth and their parents; The growth of the internet, computer games and social media. Plot Canada’s declining birth rate since 1970 and you have a mirror image of Scouts Canada’s decline in membership. A good percentage of our Groups are sponsored by churches, which have also seen a drop in membership.

In fact, Scouts Canada has always been an inclusive organization – we simply made a formal policy of it in 2001. Regardless of the decision that Boy Scouts of America reaches in this matter, the fact remains that Scouts Canada has always been an inclusive organization, and Scouts Canada is growing.”

John Petitti, Executive Director – Marketing, Scouts Canada

Resources from various religious organizations discussing their stance on sexual orientation.
Religious Society of Friends (Quakers)
Buddhist Churches of America
Evangelical Lutheran Churches in America
Central Conference of American Rabbis
Unitarian Universalists
United Church of Christ
Church of England