Can someone please help me. I have several pieces of music for vocal that I want to be able to play on the clarinet. Can someone please tell me how I go about transposing it? If for example it is C major - how do I rewrite it to sound ok on the clarinet??

Thanking you

do you want just to play the music on a clarinet, or to play it while someone sings? if you just want to play it alone on clarinet, you don't really need to transpose it- just play what's written, and it will just sound in a different key. but it'd sound fine.
if you want to play with someone singing in teh original key, though, you'll need to take everything up a whole step- clarinet plays in Bb, meaning when you look at the music and it says "C", it'd match the Bb on a piano, voice, or other concert pitch instrument. so take everything up a whole step on the clarinet to sound at the intended pitch.
C->D, E->F#, Ab->Bb, et cetera.

I'm just learning to transpose at the moment.
Problem I'm having is to know when to put in flats and sharps.

A simple way to transpose a concert pitch score into a clarinet one(Bb) is simply to add 2 sharps or take away 2 flats from the key signature

Bb,Eb would become a C major(no sharps or flats)
F# would become F#,C#,G#
Bb would become F# (take 1 flat and add 1 sharp)

Then play the notes 1 note higher following the changed key signature.

C becomes D
D becomes E....

Thanks, that helps a lot.

Thanks, that helps a lot.