I personally prefer picking up girls at daytime. I don't like clubs so much.
I find women more attractive at the day and like the enviroment more for some reason. Unfortunately most techniques are based on club situations. So I cant use them so much but only a few tips...

Can someone recommend me a book that focuses mostly on picking up girls at day? not nightclubs?

I have only found till now Day Bang book that has some good reviews on amazon... Is it worth it?
Is there a better product in your opinion out there?

Here's what you do...

Step 1: Go out on the street. Talk to 20 girls. Do whatever you think is right. (you will probably fail.) Get the experience doing it so you know what doesn't work.

Step 2: Learn any type of theories, methods, routines, whatever that you can add or adjust to your game to hopefully improve.

Step 3: Implement whatever you learned and try it out for yourself. Talk to 20 more women. See if what you learned helped your game or hurt your game. Get the reference experience so you know for next time. (because again, you will fail most of the time.)

Step 4: Repeat steps 1 through 3


Keep following that system.

Try new things. Have no expectations of outcome. And don't be a fucking pussy. In order to understand ANYTHING and develop the skill, you have to actually go out and do it and get first hand experience. Otherwise, none of this shit will make sense.