Out of room?

People in the blogging world, I need help!  I just noticed that I am on my 302nd post!  I went to upload the kids' new pics. and I got a message saying that I have run out of room for uploading pics.!  What do I do now?  I am so not a techie, I read the instructions, but they didn't mean much to me.  Can anyone help me please?  Thanks!!