I am making good progress with my study programme. I completed my first pass through McDonald's Starting Out: Queen's Gambit Declined, and have worked on my responses to the other QP games and the remaining opening moves by White. I am now on my second pass through McDonald's book. It is indeed a good practical introduction to the QGD, and the illustrative games are very instructive in themselves.
Its time for a few words on the other sources that I have used.
How to Beat 1.d4, by James Rizzitano. This book gives some useful suggestions for defending against the QP games without an early c4. Rizzitano also recommends the QGA, but I decided that White has too many threatening lines for my liking in that opening.
Fundamental Chess Openings, by Paul Van der Sterren. This is great single volume introduction the strategy and main lines of all the chess openings. You also get a lot of paper for your money. Highly recommended!
Batsford's Modern Chess Openings (15th Edition), by Nick de Firmian. This is no longer "the chess players' bible," but it is still a useful single volume introduction to the main lines of all the openings. I find that it also provides a good "sanity check" on the level of detail to study. If I am studying opening lines at a finer level of detail than MCO, I am probably doing too much. As with the previous book, you get a lot of paper for your money.
I have also made heavy use of Shredder on my iPad. Its a great little program for playing through games, and providing analytical help as required. I have also been using the Chess Base Online app on my iPad. This is, again, very useful. It provides access to on-line opening and games databases, and has Stockfish on board to provide analysis. Its still full of bugs, but has become less troublesome after the last update. I can now reset it by going back to the menu, whereas before I had to delete and reinstall the app. Hopefully, Chess Base will fix the bugs eventually.
I am also making good progress with Neishtadt's Test Your Tactical Ability. It is a very good book, and I expect that his more recent enlarged book is even better. I am also plodding through my various problems of the day, and adding to my file of easy tactics that I had difficulty seeing.
I have just taken delivery of a new toy: a Novag Citrine chess computer. I have been working from diagrams for a long time now, and I am having difficulty visualising with a set and pieces. Hopefully, this little baby will help me fix this problem. It is supposed to be USCF 2330 (or about FIDE 2000 or ECF 170), but I was soon a rook up in my first game. The Citrine was playing at an average of 30 seconds a move, and I may have taken longer. Nonetheless, it should do the job. Computers at this level win points by hanging on in there and exploiting blunders. I will have to make sure that I do not make any! The Citrine has a beautiful set and board, and its nice to have a retro machine that cannot hammer me! If I want to be taken to the cleaners, there is always Shredder, which is formidable even on the iPad. I expect that a cheaper machine would have done the trick, but I thought it was worth paying a few pounds extra for a nice one.