Read through the links they gave you to see where the problem may lie If you need help understanding anything, just ask.
I think you had clicked on your ads. Google noticed that and send you a warning. Don't repeat that again.
You should be happy that they didn´t close your Adsense account. Try to find out why Google Adsense team has written this message for you. Maybe you can find it who is clicking on your ads.
maybe your ads are copied and run on some other sites. to prevent this just go to your adsense acc and limit the sites u want the ads be valid on. thats for sure.
I would be checking out your stats very carefully at this point. Any mega hits from a certain source? You may have been targeted by a group that found a competitor running ads on your site and started clicking a lot. Open up the dialogue with google and continue NOT clicking on your own ads...thats my best advice.
I think you have should not do anything.As i my self once recieved such an email about 2 years back, when i made a click on my own ad to see how much i get for a single click and then after some time i logged in into my account.And the next day i recieved an email just like your one.So its not a big issue but keep control that don't do any mistake again.And if you think that you didn't did any click and you recieved this mail then ask adsense.They will give the states. Hope it helps. Regards: Arif
Make sure nobody in your household, especially kids, accidentally click those ads from your home computer.
I agree with the many others that you are very lucky, If you are not clicking your own ads, THEN make sure to find BETTER sources of traffic Hope that helps