How to use historical open & close price data to determine trading opportunities - trends - etc?

General
1

  1. what does it show if the opening price is gap-up than previous days closing price ?

  2. what does it show if the opening price is gap-down than previous days closing price ?

  3. what does it show if the opening price is same as previous days closing price ?

2

you can read 

http://zerodha.com/varsity/module/technical-analysis/

http://zerodha.com/varsity/chapter/chart-types/