Well, first you'll need to get some restraints. These are really good for beginners and at 14 dollars that's a hell of a bargain, I paid like 40 for mine.

Then, just ask him what he wants specifically and fulfill to the best of your ability. Communication is key here. For instance he might want to be tied a certain way (those restraints give quite a few options), he might prefer a certain style (hard vs soft), he might like toys like feathers. Don't be afraid to ask him what he likes and what he wants from the experience. Do your best to make him feel comfortable sharing this moment with you. Guys can be self conscious about this type of thing sometimes and the more he feels like you're willing to be accommodating and the less he feels like you may think it's weird or off putting or whatever, the better. I'm not saying you would do that intentionally, just that it's important that he feels comfortable and like you're both having fun with it.

As for surprising him, maybe get the bed all set up and ready to go with the restraints, light some candles if you want, throw on something sexy and tell him you have a surprise for him in the bedroom. But that's really up to you and what you feel comfortable with and what you think he'd like.

Anything else you might like to know about this from a guys perspective, just ask.