When it comes time to create your research poster, it might be helpful to have a template for a 36X48-inch file. So here are a few sites that have those, in different formats, depending on what you want to build the poster in:
General tips from University of North Carolina
A collection of formats
There are many, many other options available. ... If you find a helpful template site, please put the URL into the comments here, so your classmates can check those out, too. Thanks!