My best advice is to go a really good dealer. If you have a Cabelas near you, that was the first place I went when I decided to try a crossbow. The first thing I found was that I did not like the very heavy front end. I also found the noise to be overbearing. I also noticed the standard scopes are pretty much junk . The salesmen at Cabelas were great to deal with though. They let me shoot about every model they had. Luckily this confused me more than I had expected. I decided to wait. Then I found a Barnett Vengeance to shoot. It is a reverse draw xbow. I really liked it. It balanced well and was much quieter. That was the first xbow I bought. I loved it.
Fate stepped in again when my truck was broken into and the xbow was stolen. My insurance company paid for it and a lot of other items that were taken. I had spent some time, by then, on crossbownation and learned about the Skorpyds. I used the insurance money to buy a Ventilator 150, easy to cock, and put a high quality scope on it. The aura is back in balance and the world is good. :)
Find a good dealer and shoot as many different models as you can. Then make a decision. As stated above, they are not as easy to master as most people think and have their limitations. But they are a lot of fun.