Yes, I learned the hard way. I did not resize my pictures and very quickly ate up space. One of these days, I'm going to go back and repost them at a reduced size.
There is a thread (I think started by me when I was having difficulity posting Thumbnails) that gives a couple of approaches for quickly resizing and also provides the recommended size to post.
I can't find it at the moment, but I'll look again later and post the link to the thread.