With Castle ActiveRecord you won't have to learn NHibernate mapping schema to have a working data access layer in minutes. For most cases you won't need to deal with ISession and ISessionFactory. Most of the complexity is handled by ActiveRecord, but if you want to do something more advanced, you will be able to do it.
To follow the steps described in the post you will need:
Visit https://github.com/castleproject/Castle.ActiveRecord and copy to clipboard the URL for Read-Only access.
Create an empty directory and select the entry named "Git Clone..." on the Windows Explorer Context Menu.
Click OK in the next screen and wait while Git is downloading the project files.
When finished, you can browse the project files in the specified directory.
The default is to build for version 4.0 of the .NET Framework. If you need to build for an older version you can edit the build.cmd file (it is actually a batch file).
The project's build platform is MSBuild as you can see from the Console Output above.
Open folder "build" which is the project's build output.
To have a working data access layer in minutes, add a reference to Castle.ActiveRecord.dll and Castle.Components.Validator.dll.
The documentation is here. Feel free to contribute.