All major scales have the same pattern of tones and semitones, i.e., the interval between the 3rd and 4th note and the 7th to 8th note in the scale is a semitone (1 fret). For the F major scale to keep this pattern of tones and semitones a B flat (Bb) note must be used instead of a B note.
Songs in the key of F major use notes from the F major scale, so songs in the key of F major will contain B flat (Bb) notes rather than B.
The F major scale contains one flat, Bb, therefore the key signature for the key of F major contains one flat, Bb.
The most common chords in the key of F major are;
F Gm Am Bb C7 Dm
As well as the standard acoustic guitar, there is another version called a Cutaway where part of the body of the guitar is cut back and reshaped along the side of the fretboard. This makes it easier to play notes high up on the fretboard, which is great for playing Lead solos on an acoustic guitar. Many players who switch frequently between acoustic and electric prefer to use an acoustic cutaway.