This is an excerpt from the SDK (I'm not allowed to provide the whole thing, cause one has to sign a licence agreement):
"The source code of a VST plug-in is platform independent, but the delivery system depends on the platform architecture.
- On the Windows platform, a VST plug-in is a multi-threaded DLL (Dynamic Link Library).
- On Apple Macintosh, it's a raw Code resource. Note that the plug's name as seen by the user is the resource name (not the file name). A folder labeled 'VstPlugIns' is searched for plugs, this should preferably be installed in the System Folder. Applications should additionally search the
- On BeOS, a VST plug-in is a Library.
- On SGI (MOTIF), a VST plug-in is a Library."
So you still don't know exactly what you need, right? Same to me. But I'm not a bad guy, I think the following might be a good resource to start with (there's some pro-developers too)
BTW the Steinberg SDK is pretty straightforward to start with...