Documentation for both the REST and the Open Architecture API comes with the product. I haven't looked at the REST documentation much, but I know the OTA API documentation contains many examples of how to do a variety of tasks through that API.
On an ALM 11.0 server you can get to the documentation by logging in to a project and accessing Help > Documentation Library.
On an ALM 11.0 server you can get to the documentation by logging in to a project and accessing Help > Documentation Library.