Chess: 5334 Problems, Combinations and Games

One resource that I can recommend if you're having trouble with basic mates: Laszlo Polgar issued a huge anthology of mating puzzles. It's an amazing resource, it is mates in one two and three in great numbers. If you're serious about training you can sit down and do 10-15 of those a day for two months and you're going to greatly improve your mate-related pattern recognition.