National debate about K-12 Science, Technology, Engineering, and Mathematics (STEM) education has given rise to questions about appropriate materials for engineering education from prekindergarten through grade 12. Introducing engineering in the early years entails recognition of the need for teachers to understand its content and poses the challenge of preparing teachers to incorporate engineering education into their practice. Teacher preparation has historically included seeking information in books, journals, and magazines, and the professional development offered by universities, school districts, and other educational entities continues to provide the majority of formal options accessed by teachers. However, the advent of the Internet has expanded the ways that teachers undertake professional development and how they prepare to present new content. An online search for open source preschool through grade 12 (P-12) engineering materials revealed a wide variety of Web sites and online documents that included curricula, lesson plans, and descriptions of activities. Narrowing the search to the P-3 level revealed that the pedagogically and content-reliable sources available are limited in number and may be difficult to identify among the plethora of information. This study begins to describe the current landscape of open-access Internet materials in the field of early STEM with emphasis on engineering. The authors offer a guide-in-progress for selecting material for teachers and parents interested in introducing their young children to engineering. The authors also address emerging pedagogical fidelity and engineering content issues.