I like this guy but I'm really just the type of girl that likes dating. I'm not looking for anything serious with this guy. I have fun with him and want to be his friend and hang out, but I don't want him to get the wrong idea. What's a nice and friendly way to tell him this?

Why do you have to tell him? Has he been wanting to be exclusive with you? Why not just slide into the conversation now and then comments about dating other guys and already being booked. ("Sorry. Can't go with you to the movies Friday night. I've got a date already.")

If you are not dating what is there to tell him. If he ask you out someplace you don't want to go, say no or don't go out with him every time he ask. Don't use him for entertainment.

And if you have to tell him, just tell him

Be honest with him. Don't mess around with his feelings.