The perfect time will never come if you wait for it; you need to make it happen. When you first start dating someone you should start getting them used to your touch. A lot of girls are surprised (not in a good way) when a guy out of nowhere just kisses them. What you want to do is work up to that. Here are three easy ways to begin working up to it. (There are more, but I'll give you the simplest). You should also be having fun while talking and getting to know each other.
1. When going into or leaving any place with a door, open the door and step aside to let her go through first. Now, place your hand on her lower back and gently guide her through. Keep the hand there only for a second, just long enough to lead her.
2. Whenever you are just standing still and want to go somewhere else, use this. For example, you are at an art gallery on a date looking at a sculpture. Look around for something interesting and then you take her hand as you start to walk off and say "let's go take a look at that". Just don't let go for a little while. You are now holding hands.
3. As you sit getting to know each other better, you can take her hand in yours. After a little while you can then lift her hand towards your lips and place a gentle kiss on the back of her hand.
Now that she's getting used to your touch, look for signals that she would like you to kiss her. A great one is that while talking she looks at your lips for 1-2 seconds and then back up to your eyes. You can even use this. While looking into her eyes look at her lips for a second and then look back at her eyes and see if you get a good reaction.
Small breaks in conversation where she stares into your eyes are also good signs. She is waiting for you to make your move so go for it. Take her hand into yours and make eye contact. With your other hand you can then move her hair out of the way or if her hair is in a pony tail you can touch her cheek. If you're not comfortable with that then take both her hands in yours and then slowly lean in for the kiss.
Now, since you are taking steps she will get the message that a kiss is coming. At anytime if she doesn't want the kiss she will just have to move away and you'll get the message. Her moving away is not the end of the world. But it can feel like it if you didn't prepare her and just out of no where tried to kiss her. Out of no where can create bad emotions towards you in her mind, and we want to prevent that at all costs.
As a man you are still expected to be the one that makes the moves. If you don't progress physically then you are basically sending signals that will put you in the friend zone. You need to show her that you like her "that way". Be smart though, I am not saying grope her and be all hands, but you still need to move forward.