What are the emotions you've thought of? Who is this friend, and how long have you known him? What do you normally do together? Has there been sexual tension between you two before? You don't seem to want a romantic relationship with him, so would both of you be okay with a one-time thing (or a friends with benefits arrangement)? Could you lose this friend if he wasn't cool with a merely sexual relationship, or a one-time thing?
As for how to get it started, if you decide to, usually these things are best when they happen "spontaneously". Act as you always have while you're hanging out with him. Maybe hint every now and then that something more is coming later. For example, stroke his leg or arm, be more affectionate with him. Drink some alcohol too, enough to be more loose than you'd normally be. Then, usually when you two are alone, you might have the impulse to kiss him. Do it. Chances are, he'll have some experience of where to go next. Realistically, there's a lot in common between the mechanics of heterosexual and homosexual sex. Ask him what turns him on sexually, and try it out when the time comes.
Most importantly, if you've come to the conclusion that you'd both be okay with a one-time, friends with benefits, or possibly being romantic, make sure you'd be comfortable with this person in the sack and afterward. Be positive that you can have fun, and that your friend would have fun too.