If you want to read the help of a WinAPI function, then Google, e.g.: SendMessage msdn
List of functions from A to Z: https://msdn.microsoft.com/en-us/library/aa383688.aspx
List of functions in categories: https://msdn.microsoft.com/en-us/library/aa383686.aspx
If you need examples: https://www.rsbasic.de/winapi-library/
Or you use the forum search or you can ask your question in this forum.
\\Edit:
I hope it wasn't a bot.
