I've been all over using Google, but can't seem to find out how to do something that I believe should be very simple. I created a circle shape on a transparent background. I want to give it an outline and have control over the weight of the line. How do I do this?

Also, anyone know of some really good on-line resources for Photoshop? The help that comes with it is extrememly redimentary and does not contain much detail.