Updating repository initial files.

CONTRIBUTING.md

@@ -1,2 +1,11 @@
-# How to contribute
-coming soon...
+# Contributing to Azure samples
+
+Thank you for your interest in contributing to Azure samples!
+
+## Ways to contribute
+
+You can contribute to [Azure samples](https://azure.microsoft.com/documentation/samples/) in a few different ways:
+
+- Submit feedback on [this sample page](https://azure.microsoft.com/documentation/samples/active-directory-dotnet-webapi-onbehalfof/) whether it was helpful or not.  
+- Submit issues through [issue tracker](https://github.com/Azure-Samples/active-directory-dotnet-webapi-onbehalfof/issues) on GitHub. We are actively monitoring the issues and improving our samples.
+- If you wish to make code changes to samples, or contribute something new, please follow the [GitHub Forks / Pull requests model](https://help.github.com/articles/fork-a-repo/): Fork the sample repo, make the change and propose it back by submitting a pull request.