Your only free option as far as Renderosity goes is to provide external hosting for the files. ShareCG has the advantage that they pay you depending on ad revenue and clicks on your page(s), and you can show people what they're going to get without needing to have a web site of your own. Probably best not to rely on it as a method of getting rich quick, though. ;) For images, then one of the image hosting sites such as ImageShack would work just as well, except without the payment. As for size, you can assume that anyone who downloads will at least have the ability to resize an image, so my preference would be "as big as possible, please". You can post the images individually, which will take time and effort; or if they fall into specific themes you could zip them up in sets and post those. Don't forget to include a readme to tell people what your terms of use are, and how to contact you in case they feel compelled to shower you with money. Might happen! :D