Do I have to know some scales before learning to read music notation? And please recommend me a good book to learn read music on the guitar.
If you are just beginning guitar, start learning to read standard notation in conjunction with guitar immediately. If you're not going to start with it, don't expect to pick it up quickly after you've been having success without reading.
I can attest that learning to read music for guitar is harder when you already have habits and methods for getting results that sound right. I have been playing guitar for nearly 30 years and I'm super slow at reading music from the staff. However, if you let me listen to a song, I'll pick up the nuances in one time through (unless it's something like Zappa). The way I learned how to play guitar past my ear, was through Mel Bay's Advanced Rock Guitar Technique by Steve and Neil Griffin.
As I worked through that book, I picked up on some patterns and created my own way of memorizing notes, finding notes, and being able to quickly read tablature. The concepts for the way I memorized the notes are explained really well in the following youtube video: Guitar Fretboard Memorization - A Different Approach https://youtu.be/sBgansfvELE
Ironic thing is that I can read music for piano and vocals just fine. I think that's because with piano and vocals, the notes are absolutely defined. The note is only located in one place on those two instruments. On the guitar, there are some notes that are in 3 different places on the neck. But piano and vocals were my first instruments.
On an important side note: From my experience, the guitar completely opened up for me when I started learning music theory in high school. Specifically, learning the major scale. I could play the major scale up and down the neck before I took that class, but I didn't understand how the pattern related to the chords of the song. So, that's something else you should try to get a grasp of.
For example, a song in the key of G maj can have the following chords in it and not sound weird... G maj, A min, B min, C maj, D maj, E min, F diminished.
Knowing that those chords go together makes it easy to figure out the one chord that doesn't sound quite right in the tablature or chord chart that you find online.
Unfortunately all the books I've looked at online would overwhelm me if I was trying to learn how to read standard notation for guitar. And they don't make the book that I learned from anymore. But with today's iOS and Android apps, there are all sorts of tools to help you learn. I suggest you try some of the free "guitar sight reading" apps to help you memorize the notes on the neck to the staff. From there most of those apps have a premium version with additional features...and the nice thing...they're typically cheaper than a book. And...YouTube is your friend. Search "site reading guitar", and you'll get all sorts of good ways to get what you want.
Do you intend to learn Classical guitar? In any case, reading music on the guitar from the treble clef is not specialized because the guitar does not transpose.
You can learn to read music on the Treble Clef in any standard theory book (which usually follows the piano convention). If you move up only one fret on your 5th string from the bottom (assuming standard tuning), that's C4 (middle C). You should be able to figure out the rest from there. The trouble with guitar specifically, is that there are multiple places on your instrument capable of producing the same pitch. You'll want an instructor to help you learn the basics as to "which fingering/position" to use "when."
If you want to play classical guitar you want:
Shearer, Aaron. Learning the Classic Guitar. Pacific, MO: Mel Bay, 1990. Volumes 1 & 2
Volume 1 is the finest book on guitar ever written, a masterwork of absolute genius born from a lifetime of teaching and playing. This is coming from the rock guy. Unfortunately it only works directly for nylon string guitars.
Rock, blues, or metal learn the notes but don't bother with the dots on the paper. If you try out for a band they give you a CD or audio files. Ask for sheet music or tab and you'll probably get laughed at. You need to play by ear, and get your hand position perfect and relaxed in the beginning. You need to get the chord changes down.
To honest I only bother with sight reading because I teach guitar.
Jazz you need to read music, I like the Arnie Berle books on sight reading and chords. I also like the Aebersold play along CDs.
To address some comments:
It's simply not a priority in the beginning for rock, blues, or metal players. I read music, I have to. However it is a skill I only use for the most part as a teacher. There is next to no music even printed in Standard Music Notation in those genres. Guitar pro does not do it correctly either. Popular music is an oral tradition, how it's learned should respect that, furthermore it won't be retained because there are few real world opportunities to use it. It's more useful to a more advanced player. Since they already know the notes on the neck, and advanced rhythms, matching it to the dots on the paper becomes relatively painless at that point.