i know that you get money from every 1000 Page impressions but what is the rules i mean is it should be 1000 every day or not ...and if there any thing else please tell me thanx
No this will be calculated for the month. If your site is displaying ads at the rate of 2$/1000 impressions. And if you can make only 250 impressions, then you will be paid $0.50. To get image ads select "Image ads only" option in the adsense ad setup page.
You get paid for whatever percentage of 1000 you get. You get nothing for the click from what I understand, and you don't have to wait until the end of the month. If someone's showing $1/impression (boy don't I wish!) and someone viewed it once, you'd get the dollar showing up in your account. You can view how many contextual vs site specific placement ad views you are getting by selecting that option in the advanced part of the control panel of your adsense stats.
And for my sites look better. I'm not sure there even are very many image ads for my area. I often see where the impression is given that image ads are the only ePC ones, text ads can also be ePC, not just images.
I think only premium adsense users get paid on number of impressions. You need to get lot of traffic like DP, in order to get a premium account
No, anyone can. Check in your advanced control panel on the left (show data by....contextual and placement, placement are per impression)