Take a class, so many cool online ones. Learn the basics for each type, block, and treatments. Do not depend on a machine to identify a rhythm, know yours.
I think it is important to come up with your own technique for understanding; like in images. For example, Ventricular Tachycardia looks like an attack of sharks on an ocean...therefore, it can be recalled by thinking of "v-tach of the sharks," or "the attack of the sharks."
Read Rapid Interpretation of EKG’s by Dale Duben, MD. This little orange book is AMAZING.
Sit at a monitor with a good tech and learn by looking at real rhythms. Sit for an hour before of after work. You will learn lots!
Practice practice practice!!
Talk to your tele techs. They spend all day looking at your strips. Find the ones you can trust and trust them.