I would like to put a picture as my Avatar,but I cannot find a way to do this. Does anyone know what I have to click on to do this?

Go to your profile (your name will appear in the top right corner of this page, click on it).  It will show you your current profile picture/avatar and just below that it should have a link saying "replace avatar" or "set avatar".  Click on that and then chose whatever picture you want to download for your avatar.
 

Thanks I will try that right away

OK that was easy. This is me and my husband of 43 years. You can tell I eat a lot of cake, and from the backdrop you can tell I also do a lot of gamling. LOL  Thanks Lizzie for the great directions.

Well done :-)