You can sell bitcoin in cex.io its safe to sell your bitcoin there but if you wanted to sell your bitcoin here in forum person to person you need to hire trusted escrow here
https://bitcointalk.org/index.php?topic=855778.0there is big 3 there which is more trusted escrow and the other escrow there.. just don't trade to other without escrow..
You can also sell your bitcoin i think in localbitcoin but i didn't tested yet to sell bitcoin there. .
CEX seems to give the best price for your BTC - At this moment they offer $4782 and Kraken is $4642, Bitfinex $4583 - But my guess is because that's cause it's not so easy to get it cash out.
Easiest to get out, and most options to send your cash to is Localbitcoins. - That is a bit hard to navigate, but pple will send cash to all kind of places. Venmo, paypal, WU, in person.