http://wickswww.freeyellow.com/ has many plans for for construction of outdoor fireplaces. You will see a "button" to click on the menu on the left side of the page.
If you are starting from totally no knowledge of masonry and brick work, you might need to check a book or recent magazine article on how to do the total job. If you have never mixed concrete for a foundation, built a form for it, and on and on, you can do it but you need to do your homework first. When you get that concrete mixed and then discover that you need to put rebar into the foundation, for instance, it's a little late. Many books are available at your local library.
Mike, when you can offer at least 2 good reasons why you will not be able to start a fire in your brick fireplace the first night that you build it, then you might be ready to start. This isn't to tell you that you can't build one. It is to see if you know enough to not waste a lot of time and money.