OK, I just have a few ideas to add to what everybody has said (and this is all from the perspective of a Christian girl who doesn't date, for whatever it's worth. . .)
First of all, I've read a couple of posts that were, in my opinion, just plain old bad advice. People who say that dating a non-Christian is OK, sorry, that's just wrong. God tells us that we're NOT to do that, so just don't. We may think, "Oh, well, I know it's usually a bad idea, but this guy is really nice and I think it would be OK," or whatever other thoughts might be running through your head, but in reality that's just indirectly saying that we think we know better than God in this case. Which we obviously don't, so don't listen to your heart, it's being deceptive.
Also, I totally intend on dating toward the goal of marriage. The reason for this? Well, look up examples of dating couples in the Bible. There aren't any. Now, I think the main reason for that is just that there was a lot of betrothal and arranged marriages, and you got married when you were like 13 back then, but the point is that God stresses MARRIAGE in the Bible, and so I think that that's probably what he intended for us to stress too. Now, I DON'T think dating is wrong, just because God stresses marriage; mainly because, as I mentioned, the way you got married back then was waiting untill your father met a man who offered him enough goats in exchange for your hand in marriage. We just don't do that any more. The most common way for us to find our soul mates is through the dating process. All I'm saying is use dating with the end that God intends for you-- marriage.
Another reason that I think that dating with the sole intention of marriage is a good idea (we've crossed into the area where this is just my personal opinion now, this is not in the Bible or anything, just a conclusion I've come to) is because, personally, I want to consider and respect my future husband. When a guy gets down on one knee and asks me to spend the rest of my life with him, I want to be able to give him the full package he's asking for. A lot of girls nowadays give everything in their package away before they even meet the guy that they'll marry. When my guy asks for me, I want to be able to give him ALL of me. I'm actually praying that the only guy I'll ever kiss is the guy that will be my husband. I want him and only him to have everything I have to offer. Now, you guys obviously will probably not take it to the extreme I take it to, but doesn't it kind of make sense? Do you want to know one day that the guy or girl that you wind up marrying has kissed 27 different people? Or told 27 different people that he/she loves them? I know I don't, and so I'm just trying my best to show the same consideration to my future spouse that I hope he'll show to me. Like I said, this portion is all opinion and I don't know everything, but this is why I advise waiting untill you are older to date. If you start when you're only thirteen, how many guys will you go through before you find your husband? What will you have left to give him?
Also, if you're concerned about whether or not you should start dating again, or when you should start dating, pray about it. Turn it over to God-- literaly. When I pray about it, I pray that God will not
let me date someone that I won't wind up marrying. And I honestly believe that God works in my life so that I don't have to worry about that. At this point in time, he has either a) not presented me with a guy who I would even consider having that kind of a serious relationship with; or b) I meet a guy who I would consider a relationship with, but he's already dating someone or starts dating someone during the time I know him. Now, b is a little difficult to handle, when it's a person that I really like, but I just think that God knows best and that he's watching out for me and taking care of me. And realistically, even if it hurts at the time, I'm glad for it. I'm praying God will help me save myself, and I believe he's doing that. So, all this to say that if you really seek God in what to do, he'll make it clear to you in one way or another. Just be watching for the answer when he gives it to you, so you don't miss it!
Anyways, I know I've basically just rambled for three paragraphs, but hopefully it'll help. If not, oh well, I had nothing else any more important to do, lol.
EDIT: WOW, that was WAY longer than I thought it was. Sorry about that!