Lots of good books out there......"You can read music" is one of my favorites. Read ONE page at a time, do not pass go until you understand that page, then move on. It is helpful to have some kind of metronome to keep you honest, or to count out loud, if you can do that in time. I don't sight read fast, but can well enough to decipher the tune, and it gets easier each time. There's only 7 notes to deal with, so easier than the alphabet. Just do it. The written note is the great leveler at any session.......and allows communication for people of varying languages!