To get the map as an image you'll need to use ActiveMapDisplay.GetBitmap() which returns a BitMap of the map at the current display resolution (which for most desktops is usually 96dpi). You can use that BitMap image with PDF converters which have APIs such as PDFSharp (http://pdfsharp.com/PDFsharp/). Unfortunately at this time it is not possible to request a map image greater than the screen resolution.
