Hi, can any one give any advice, recomend a book or website.
Anne Butterworths book 'Harmony in Practice' is the first book i have come across which gives a brief summary (p197) of the practices used in composition to represent joy and happiness, or sad and sorrow in music.
I have an interest in music composition and i'm trying to elaborate on this topic, particularly when considering comical effects in music compostion.

can any one advice

If you are looking for comical effects, anything with scherzo in the title would be a good start!

I've always found the music of Poulenc to have a very wistful air to it. I think that this is because of his use of intermixed major and minor chords, but I don't know if anyone else thinks that way.

The Language of Music. Deryck Cook. Oxford University Press. 1959

I would watch out if I were you!! I have recently finished my first composition at university, and I put in lots of tritones because i wanted to create a real sense of eeriness and distance from my first section, only to be told that tritones were considered scary and eerie hundreds of years ago, and that rock bands did things in the 60s and 70s that shocked and alienated people. Very annoyed at my tutor because he is an absolute nincompoop in my opinion! Just be aware of who your potential audience is and whether you are writing for yourself or for some sort of assignment. In my experience tutors and teachers today are hugely keen on contemporary techniques, and some of my fellow students from 2nd year reported that they composed tonally for their first compositions and recieved low marks, and when they used contemporary/atonal styles their marks were much higher.
Sorry for the rant! I think it would be a good idea to remember that what sounds comical to you may not for someone else. You need to try and create that sound without the listener needing to read any program notes to work out that its supposed to be comical. Good luck!!

If you want to convey anything of your experience, emotions, sensations, you have to compose from the heart. That doesn't mean that you shouldn't be atonal if you want to, although it's extremely difficult to compose anything completely atonal while preserving some kind of coherence.

The only way to find out how to represent different emotions is to study how the main composers have done it. It usually means studying scores unless you've advanced enough to work out what's going on without recourse to a score.

Good luck.

PS. Worth noting what pianosingkimbo had to say. Nobody but nobody can teach anyone how to create even if these composition professors make a good living from it. They can teach you tools of music composition but they can't teach creativity.

Sympathise completely! I would go as far as to say that "lessons" in composition did more harm than good in my case. It's consoling to remember that Debussy had the same kind of trouble in conservatoire!