I would make this post as brief as i can and point out some key factors that you must follow to get approved for adsense program. Note that i am considering that you have just started to make a blog or a website and have been pumped by online success stories and now you want to get approved for adsense and start earning dollars too.
So lets get started and discuss the basic things that you must follow before you apply. Though there is no harm in applying without any stuff on your blog but it wont be of any use as you wont get accepted. So first you should have believe in your self that you are no different than others who have adsense on their blogs. This is important as this provides you with motivation that you need to create content. Ill get to it in a second.
Content, the KingKong!
First of all you need to keep in mind that there should be "something" at your blog. Yes i know this seems obvious but there are still thousands of people who apply with post less blogs. The template it self is not enough my friend. So to get on safe side you should write at least 5 post at your blog of about 300 to 500. Note to get some traffic (around 40 to 50 page views) you should follow the keyword technique.
Keywords are Queen!
By this i totally mean to add a juicy heading. Juicy for people plus more importantly juicy for the search engines. The easiest way to implement this is searching on Google itself. Less time consuming then searching for keywords on Google keyword tool and works out really well too. Say if you are writing an article about photoshop tutorial and you need a search engine attractive heading you should go to Google and enter what ever you belive you would have searched for, if you wanted to search for photohop tutorials.
I would have typed in may be like "Photoshop tutorials for beginners". It doesn't ends up here. Now note the headings of the top 5 searches that Google displays Say i found one saying "Top 20 Photoshop tips for beginners", then you should also choose something related to that. Thats the best way to search for keywords and it helps a lot.
So by the end of 2 weeks of articles posting with keyword rich headings you would start to get around 40 to 50 page views. That's a totally rough sketch. So now you have reasonable content plus some views too, now you should go to apply for adsene.
Don't Break the Rules!
Also keep in mind that your blog follows and respects Google's adsense policy. Your blog should not contain any pornographic content, no excessive use of links etc. By this i mean that you should make sure that your blog doesn't have a list of thousands and thousands of links on a particular page. I had a blog for YouTube Sub4Sub, if any of you may know about this term- anyhow i had many links on the blog so Google didn't accepted me for Adsense. Later when i removed them it worked as i already had some content and views.
Actually Views doesn't really matter but what matter is content. And that's not difficult to build. Notice how i am in a conversation with you by the means of this post and it gets so easy to write once you start talking to your friends. Isn't it?
Once you believe you have some posts out there and your blog adheres by Google's Policy you can definitely apply.
Dont Loose Hope!
This is one of the most important part brothers and sisters. I had a blog where i had all the content set but for some reason Google wasn't accepting me but i didn't loosed hope and i kept on applying. Believe you me, i got accepted with the same issue that Google was pointing out. So thinking that once you get a "NO", than there is no hope is totally wrong to believe.
If you have followed what i have mentioned above and still you aren't getting in the Adsense program then i would recommend to keep applying and build more content side by side and you would get in for sure. (You should apply for at least 10 times before you go to re-review your blog if it doesn't get accepted)
Best if luck !