Before you begin building your poster, ask yourself: What is the central message I'm hoping to convey with this poster? This could be why the research that you did was important, a particularly surprising or interesting result, or how you plan to expand on the research in the future. As you begin to design your poster, keep that message in mind; the choices you make about the poster's content and, to a lesser extent, design should be made to support that central message.
Research posters, by and large, follow a general set of guidelines without all being the same, much in the same way that research papers often follow a familiar structure:
It's a good idea to outline the key points you'll need to include while making a rough sketch of the poster.
Image from Indiana University's IT Training Tips blog
This will help you figure out how much information you'll be able to include, what kind of graphs or charts you may need to make, and how the content will look one the poster when finished. No need to get fancy, this is just a visual outline to get you thinking about the process.
It's not always easy to find examples of research posters, especially in a specific subject area. Here are some general examples of how a research poster can be set up:
Another place to look for samples could be to check repositories such as DigitalCommons, which is primarily used for articles but does also contains some research posters:
Adapted from the guide "Creating Research Posters" originally created by Clayton Hayes, Wayne State University Library System. https://guides.lib.wayne.edu/posters