Here are some instructions to help you out:
Go to http://www.un.org/en/
Under "resources and services" click on "Documents"
There you find the UN Charter, the MDGs, Treaties, a Research Guide that explains how the organize UN docs--very good to read--and the ODS or Official Document System. Click on ODS and then you can do searches for resolutions on different topics.
hope this helps! Happy Researching!