Best Book to learn endgame (from beginner to advanced)

First, please give a review of the books you do have! (I have another book of Giddins that I think is excellent.)
As for your question, if your rating of about 1000 is accurate, I'd suggest first a thin book that covers all types of endings starting with how to checkmate K&Q vs K, like Averbach's Chess Endings: essential knowledge. There are several other good choices here.
At 1000 very few games will go to a tricky theoretical ending. So I'd suggest next one on complex endings / endgame strategy like Chernev's book: Capablanca's greatest endings.
Then do the first book again then the second again. After that you should see your rating jump, a lot, and start winning drawn endings against higher rated players. Following those two there are lots of great choices but those are the 2 I wish I'd started with.