When you open your Junk folder the contents there usually have a box beside each item. Check mark the box you wish to save or redirect, then go to the top of that page: there should be option to Delete, Move (ie to another place, like your Inbox), or Not Spam (which should automatically route that checked item to your inbox. Once in your Inbox, click on the sender's address and you should get an Option to add to your address book. That should solve your problem for the future.
I have known your pain.....