Keep one hand on or near the pause button. If you read a sentence and don't understand, stop the recorder, rewind it, and read it again. There are tone, volume and speed controls on the player. Adjust those controls for the material you are reading. If it's easy to understand, you may want to speed the recording up.
Beginners start by leaving the speed control on normal or only slightly accelerated.
Read a paragraph and then stop the recorder. Ask yourself if you understood what was read. If the answer was yes, start the recorder again and read the next section. Use a prearranged plan to monitor comprehension, importance of details, fatigue and general learning rate. Practice these skills and others that you learn to become expert at reading and learning.