Win32 API programming help?

I need to write a program to change some registry settings in Win ME/XP. So i wrote a simple app in vb 6.0 using win32 api but the result was not very good , mainly due to the lack of documentation in API functions to handle the registry. I tried the MSDN site with little help.
Can anyone provide me with some good help, URLS or perhaps code samples. Please help me,(code in VB 6.0 only not VC++)
Thanks