Find one that you like. Preferably not enormous. You can resize it easily, I believe even google will lead you to an image editor where you can resize it and save it. Keep it within the 50x50 brackets dimensions-wise like with any avatar on bluelight. Upload your resized gif to something like tinypic or imgur and paste the direct link to the image under the edit avatar option in settings. Or you can use the other option for uploading and just upload it straight from your hard drive and onto bluelight, then you don't have to worry about a third party hosting your file and it potentially being deleted or down at times. Just make sure the gifs size doesn't exceed 50kb, and you should be good.
