http://bitcardkpomtp6vdgth4aat3yblm75kwcklsjr4grpdpmhu3sh67ikyd.onion/bitcoin.html
Read through them before submitting the trade request, if you don't agree with them, you can go back to the previous page and choose another advertisement. To start the trade, type in how much Bitcoin you want to buy and click the "Send trade request" button. You'll be once again shown the trade terms, read them carefully one more time and make sure you agree, then press "Accept terms".