Publishing your template from Photoshop isent a very hard task once you get the hang of the how to do it and learn to use the tools correctly to carry out the task.
To do this you will need to use your three programs, Photoshop, Image Ready and then Dreamweaver. In photoshop and image ready will be used to set the template up for publishing in Dreamweaver. So you will basicly be slicing the image into different sections etc.
Since you dident make the template yourself i am not sure if the PSD you got has already been sliced or set up to be imported into dreamweaver so it makes it a little hard to help out there. It will also take a long time to explain so here is a link to a website that has a large tutorial on how to publish a website from Photoshop to Dreamweaver.
It is aimed at beginners to it should be quite easy to understand for you.
Tutorial - Click Here
Hope that helps.
- Jye