The National Organization for Women is a group that was created in 1966 with the purpose of focusing on women's issues such as equal rights, equal pay, and reproductive freedom. To achieve the ends, NOW has been active in supporting many pieces of legislation that guarantee women's freedom of choice and which prevent discrimination against women. It has also served as a strong voice in opposition to acts that restrict women's freedoms or seek to limit protections for gender equality.
NOW has been active in opposing legislation that restricts women's reproductive freedom, supporting the Freedom of Choice Act (FOCA) and opposing the 2003 Partial-Birth Abortion Ban Act. NOW has also been at the forefront of the comparable worth movement which uses the concept of equivalence to argue that the Equal Pay Act (1963) requires that jobs of similar skill levels not have pay differentials with masculinized jobs being paid more than predominantly feminized ones.
One important piece of legislation supported by NOW was Education Amendments of 1972, which included Title IX, guaranteeing equal educational opportunities. NOW has also strongly supported marriage equality for gay couples.
More recently, NOW has supported H.1718 in Massachusetts, which supports paid medical leave for people working in small businesses, acts in the state of Washington to ensure that foreign workers are informed of their rights, especially rights related to violence against women and legislation to require full truth in advertising for "limited service pregnancy centers" that claim to offer abortion counseling but actually do not provide (and often oppose) abortions. On a national level, one of NOW's major priorities is supporting the Paycheck Fairness Act (S. 2199).
The National Organization for Women supports and opposes a great deal of legislation at any given time. Perhaps the best way for you to find a great deal of information about this is to visit the legislative action section of their website. You can find it here.
At that link, you can find many examples of legislation that they support and oppose. For example, they support the Violence Against Women Reauthorization Act of 2011. They feel that this law would do important things to protect women from various sorts of violence such as domestic violence and sexual assault. On the other hand, they oppose the Child Interstate Abortion Notification Act, which would make it more difficult for teens to get abortions outside of their own home state.
The National Organization for Women is an organization with multiple chapters throughout the U.S. Because the organization has such broad reach, there are significant examples of the organization's involvement in policy discussions on both a local and national scale. Generally, however, NOW focuses its energies on legislation that relates to women's bodily autonomy and health (like abortion or access to birth control), equality in the workplace (such as access to affordable childcare), violence against women, and access to resources for lower-income women.
As an example of legislation that NOW has fought against, take a look at this article by Anita Rios, the President of Ohio's chapter of NOW. Rios published the article in an effort to stop Ohio's proposed 20-week abortion ban. In the article, she discusses the ways that the ban would impact low-income women by limiting their access to a legal service more readily available to women with monetary resources and the ability to travel. Many states have attempted to pass laws limiting access to abortion, and organizers like Rios have spoken publicly against those bans and reminded legislators how the proposed laws could affect disadvantaged women disproportionately.