Just purchased Lightroom 3 and one of the first projects that I have been asked to do is create a 36 x 54 poster print for my grandson's bedroom. I have a Sony Alpha 10.2 megapixel camera, image size 3872 x 2592 pixels in RAW. I am new to doing such a large image and am not confident that I could get the image quality for this size image from my camera, but want to try. My basic question comes from the way Lightroom resizes images. It can only be done on export, much different than in Photoshop where there is a simple dialog box and you just adjust the size and PPI that you want. I also understand that to do something this large that enlargements should be done in smaller incremental steps rather than just jumping to the finished size at once. Question is: in Lightroom, can I export the image to an enlarged size with desired PPI, then import that image, and then resize again a little larger, doing this sequence in a number of steps until I get to the desired final size? I would NOT use JPEGs to resize but rather TIFFs, and then save the final image in either PSD or DNG depending on what the lab would like to work with, maybe a JPEG if they prefer. Or am I missing something and there is another way to enlarge in Lightroom? I am thinking the final image should be at least 200 PPI or so. The files will get really large beyond that. Does Lightroom interpolate or resample to add pixels like Photoshop, or is the process and thus the results different? Last question: if this can be done to satisfactory quality, do I do all of the Lightroom developing on the RAW image out of the camera, then enlarge, or do the enlarging first, then developing. My logic tells me to do the former for a variety of reasons, but my logic may not be correct. I am hoping someone can give me some sound advice on how to do this.