Blogger stuff

I have been online for hours trying to upload a picture into my sidebar. Also, I'm trying to find the code for a most recent comments function in my sidebar. Now I'm trying to convert an image from tif to something else that will upload into imagehosting and then somehow I'll get it into my blog. I know just enough to modify my template and colors, but not enought to do otherwise than keep plugging away by trial and error. I'm getting frustrated.