First, practice is the most effective way to learn to sight read sheet music. As a result of this, practice as much as you can. You should refer to the book by Mel Bay “Sight reading for contemporary guitarist” which you can find on Amazon’s site. The book is about the guitar but it can be used with other instruments as well. It can be a valuable resource for you to help sight read sheet music.
Sight read sheet music
The book is helpful up to a certain extent but it is better if you learn to read sheet music by yourself. You should have sheet music without any TAB so that you can start practicing to read the notes. Train your eyes and mind to learn the position of each symbol on the line in order to spot the note and play it immediately without taking much time. This is not that easy but with some practice you can ace it. On the other hand, visit Free-scores.com to get free sheet music for any instrument you want.
Begin reading with easy notes
Try to master a few simple notes before venturing for the hard ones. Your aim should be to memorise the position of the notes so that you immediately know what you are playing. By doing this, you will play the song in your head by just by having a glance at the sheet music. It is best to take your time to read and practice in order to learn sight reading.