Read Read Read and Read and then do whatever you want, this is what I advice to newbies.
You should research a lot before investing / selling your bitcoins especially if you are a beginner. You should not rely on a single opinion, spend as much as time for reading about various views.
You can start selling bitcoin by selling it to the reputed member here on bitcointalk to make yourself feel comfortable and then try other services.
I think localbitcoins is the most trusted site where you can sell your bitcoins. Whats more important here is that this site has users from all over the world and you can easily choose a trusted member from your country and even perform face to face transactions.