B Major Key Signature

Going from the key of A to the key of E, we added a fourth sharp to the key signature, D#.
Now going up another 5th from E to B, we add a fifth sharp to the key signature, the 7th note of our new scale, A#.
So the key signature of B is five sharps, F#, C#, G#, D# and A# and the notes that make up the B major scale are B, C#, D#, E, F#, G# and A#.
 

Guitar Chords in B

Guitar chord diagrams above and degree of scale, chord name and notes below make up the key of B Major.
I Major = B Major - B D# F#
ii minor = C# minor - C# E G#
iii minor = D# minor - D# F# A#
IV Major = E Major - E G# B
V Major = F# Major - F# A# C#
V7 = F#7 - F# A# C# E
vi minor = G# minor - G# B D#
vii- = A#- - A# C# E