Adsense in my blog

Please tell me how i can show google adsense after the first 3 posts of my blogs each page. there is 10 posts on my blogs each page since google is allow only 3 ads please tell me how i can do that. and tell me where to put adsense code. as im very new wordpress user.

Thank You

 

or tell me the best wordpress adsense plugin with link

 

Maybe better block advertising in sidebar?

 

I've never used it myself but people talk about Adsense Deluxe as being a good plugin. You can find this at: http://www.acmetech.com/blog/2005/07/26/adsense-deluxe-wordpress-plugin/

 

I posted that with coding (better than any plugin)