When you first glance at a crochet pattern, you will likely be confused by two things: the symbols and the abbreviations used. Thankfully, the symbols' meanings are standard across patterns.
Symbols
[ ] - follow directions within square brackets as many times as stated
[ ] - follow directions within square brackets as many times as stated
* - repeat directions following this asterisk as directed
* * - repeat directions between asterisks as directed
" - inches