ActiveX Control Download ?

I have a couple of questions
Is there a special parameter you need to pass in the codebase parameter so the client will download an ActiveX control?
Everytime I try to view this page with a machine other than my own, I first get a security warning, then the control won't initialize. I don't think it is downloading the source files if the machine is missing the control

<OBJECT classid=clsid:E5C86450-63DB-11D5-B451-000102699E2B codebase=cabs\ACXTestCtl.CAB id=acxtest1 VIEWASTEXT></OBJECT>

Does anyone know of a tutorial that will take you through the "Hello World" project for building your own ActiveX controls then embedding them on a web page? I've been able to initiate and install/download on some published components, but any that I have made myself are bombing.

Second Question.

How uniqe are the clsid's? Isn't there a possiblity that a clsid that is generated from my server could be duplicated somewhere else? How is this prevented? Thanks in advance.