Err...best advice is to actually go and read up on the dozens of pages that adsense produce for you to read through prior to applying. You're far better reading up there than asking here. After all they set the rules no us. Also whilst the blog post is good, by going direct to the adsense website then you know you are reading the latest guidelines
It is well explained in this article.. I recently followed this post and got my Adsense approval in 3 days...Good luck... http://www.whizblogger.com/google-adsense-approval-within-3-days/