Why dont you simply read the MSDN Doku to answer this Question ?
Create an ImageList and send TB_SETIMAGELIST message to the Toolbar control.
g_hImageList = ImageList_Create(..)
SendMessage(hWndToolbar, TB_SETIMAGELIST, (WPARAM)ImageListID, (LPARAM)g_hImageList);
For detailed explanation on how to use the Win32 Toolbar control, you can read this MSDN article.
http://msdn.microsoft.com/en-us/library/bb760446%28v=VS.85%29.aspx[
^]