Authors of informational text employ a variety of structures to assist the reader in finding information quickly and efficiently. These might include a table of contents, an index, bold or italicized text, glossaries for specialized vocabulary, embedded definitions for specialized vocabulary, realistic illustrations of photos, captions and other labels, and graphs and charts.
The thesis statement can be at the beginning (these are usually the boring beginnings), you'll usually find them near the end of the introductory paragraph.
