How can I know if the guy I'm talking to is worth my time and patience? What indications can he show to prove to me that I'm not wasting my time on him?

You could try reading a book on body language,most people can't fake it I'm reading a book on it at the moment its really interesting as well as knowing what people are thinking with out them actually telling us.their body is telling us in noverbal movement

My book is called- collins need to know? Body language

I think that if he shows he cares... and treats you nice, doesn't lie to you, and is just a great guy all around... you won't be wasting your time at all..

Honesty, communication, understanding, and compassion.
What more can you ask for?

Questions like yours make me nervous. It makes me wonder if my advice is going to be used to persecute some helpless shmuck who has no idea how needy someone can be.

Do you understand my concern? Of course I understand you don't want to waste time on losers and bad matches, but does that mean when you first start going out with someone they have to prove themselves to you in some specific way?

Wait, yes, it does mean that. Hehe. Ok, so you and I agree that you need to be making judgements and not waste time on losers.

BUT. That doesn't mean you are off the hook. Far from it. I believe that your most important task in dating is keeping it honest. BOTH OF YOU, though, not just the guy. To get to the honesty in a relationship means you have to sit through the dishonest courting that comes in the first few months. That means EVERY TIME you choose to date someone, you're committing a lot of time to waiting that period out.

If you're honest, and keep your feelings out of it, most of the time you will discover you're dating a bad match and one or both of you will realize it and end it.

Here is where I think you and I differ. Does breaking off mean you wasted the time? I don't believe it does. I call that a success. A failure is not figuring out you two aren't compatible until after you're married... with children... and debt...

So, my best advice is go slow, waste some time, but be honest, pay attention, but make sure you're having a good time and continuing to develop your individual life outside of your dates, OK?

And you make sure that he is really into you as being romantically into you!
Some guys like you as a friend, now, they are good guys and probably really treat you like a good friend without any other intentions if you are a good girl.

Don't fall easily, and don't be judgemental. Ask around, see how others see him? See who his friends are... you know? Who he hangs out with says a lot about him.

Never ever rush into a relationship and remember if at the end he is not the one or he doesn't like you as much as you thought... move on! It is not the end of the world, many people are still waiting for the right one!