Let's start with this picture below so you become familiar with braille.:
The Braile Alphabet:
You must memorize these to understand braille.
Step 3: Phrases and Abreviations
There are also the phrases and abreviations. For example cd is could. Abv is above. Qk is quick and sd is said. For the rest of these you are on your own. The link below should help you out if your still confused.