I have this book also, it is wonderful. The best thing you can do is find people you know who have books, pick through them and find the best fit for you. Then get your hands on an ECG packet, we have one at work for new hires to do their ECG interpretation test with. I have a few from school and work, they have many different rhythms in them, and just practice. But understanding the way heart works is key, if that doesn't make sense nothing else will.