Most chess tactic software (from chessOK) are based on Soviet chess books. They are well-designed to teach kids. Kids can learn the themes, or topics, or strategies if you like to call them this way, one by one. Learn it and practice it. Repetition is the key for learning.
You can also test yourself by selecting levels, number of problems, and time. The software will pick problems to test you. The intensive tests can serve as effective training.
If you finish one CD, you know you have accomplished something. This positive feedback is very important for motivating students to work on more difficult CD.
The three software I recommend are:
- Chess Tactics for Beginners 2.0
- Chess Tactics for Intermediate Players
- CT*Art 4.0
All of them and other chessOK software are available at my online MiniStore.
("Training Package for Intermediate Players" includes last two and other 3 software)
Most chess websites have large collections of problems, but they are not well organized and cleaned. The themes can jump around when you work on problems. It's not easy to train by repetition. The difficult level can change dramatically. And you never feel you achieve anything because you can never finish the database.