Functions, structures etc.
Functions/APIs:
Structures and other related items if any: Part 1
Further reading and digging:
Microsoft Visual C++, online MSDN.
Structure, enum, union and typedef story can be found in C & C++ struct, enum, typedef etc..
For Multibytes, Unicode characters and Localization please refer to Multi-byte & Unicode 1 (Story) and Multi-byte & Unicode 2 (Implementation).
Windows data type information is available in Windows data types.
Check the best selling C / C++ and Windows books at Amazon.com.