The best way is it start learning the C note on each string (only up to the 12 fret because, it repeats itself from there). There will only be one C on each String to learn. Once you have learned this, go on to learn the B and so on. Miss out the sharps and flats as that will come easier once you've learned all the abcdefg. It may sound tedious but spend a week on each note and u'll know it off by heart in 6 weeks!