The introductory paragraph is a specialty paragraph that introduces the reader to an essay. Below are two examples of well structured introductory paragraphs. They contain the three basic elements necessary for all introductory paragraphs: the topic sentence(s), which define the topic and "grab" the reader; the thesis sentence, which defines the writer's point of view regarding the topic; and the outline sentence(s), which describe the main topics in the body paragraphs.
The following are two examples of introductory paragraphs. While you certainly don't have to follow them word-for-word, these "exemplars" provide a good model to follow if you're not sure how to write your first paragraph.
In the first example, we see all three elements. As usual, the topic sentences go first, followed by the outline and thesis. The order of these elements (especially the last two parts) may vary in your own introduction.
In the second example, we see a more sophisticated introductory paragraph, but all the basic introduction elements are present. The outline indicates that the body will start with an analysis of Paul Barker's position, followed by an analysis of Hiemstra and Janzen's position. These analyses will then be followed by an evaluation of both positions.
The outline often follows the thesis, so feel free to explore different structures; this example is by no means the only way to organize your introductory paragraph.