C++ Alt-Tab Hook

I've looked at some sample code to develop a alt-tab keyboard hook but I don't 开发者_如何学JAVAseem to understand the whole thing. I understand that a .dll is written and that somehow gets injected to all the processes.

Is there a top to bottom guide on how to do this from writing the dll to loading it?

Keyboard hooks are a really shared resource, i.e. it depends on programs not stomping on each other. It's always a bit risky to insert one into the chain. Can I ask what the hook is for? What is it you're trying to ultimately accomplish with the hook?