Dating is supposed to be a way of getting to know someone, with the intent of marriage later on. Although, it's a modern phenomena, and is often used as a form of marriage without the commitment. Many dating couples share a level of intimacy that should be reserved for marriage. But, without the legal contract, there's no reason to stick around long-term, and it often leads to a break up / broken hearts later on.
Dating - in my opinion - should best be approached from a traditional matter, i.e. courtship. Courting is a way of seriously getting to know a potential partner, with marriage in mind, and from a Biblical perspective. Physical and emotional intimacy is reserved for only after marriage takes place, and physical touch is usually restrained for the most part (with the exception of a kiss on the cheek or holding hands). The families of both parties are also directly involved, usually meeting the suitor in advance.
I don't think it's wise to date an unbeliever, even though they may be very attractive and may seem like great marriage material. The person we date will have the most significant impact on us and our walk with God, which is why the Bible advises us to not be unequally yoked. I once advised a friend of mine (who identified as a Christian) not to marry an unbeliever, but he did so anyway. Ever since, I noticed a change in him over time as he drifted more and more from God. Someone who isn't mature spiritually (or who doesn't love God / isn't yielded to the Holy Spirit) can also be used by the enemy to attack the marriage, or the believer themselves. Since we share the deepest level of intimacy possible with our partner, the most significant attacks from the enemy can also come from the person we're married to.
So in short, it's best to wait for God's best, and to maintain prayer with Him when considering a partner. Dating - and marriage especially - can be a very exciting adventure to partake in.
But, should also be approached carefully and with discernment.