I want a serious relationship?

I'm Single and have been for a while. I stopped dating 3 months into high school because i could see that It wasn't a good idea. I was too young and my social circle was very limited. I'm considered quite smart for my age and am graduating 1 year earlier. I'm thinking that i would like a man a few years older then me. I'm almost 18 and would like someone between the ages of 21-25. I'm not a real romantic type of person. I don't believe in love at first sight and soul mates. But I do believe in Beauty is in the eye of the beholder. I believe that You have to have a physical and emotional connection with someone for the relationship to work. A emotional connection is great but i don't think that it will keep u together as lovers, more like just friends. As for the age I know a lot of guys don't really want a girlfriend that young because they think others will look at them like they are creeps. the thing is, i'm only young in age, not mentality. I don't want to date someone my age, because of the maturity issue and I believe they are still at a different stage in life then me. My question for you is how do you think I should go about looking for my significant other?