One point I believe is overlooked for new AdSense site developers is the preparatory work that goes into a site before launch. I believe this is a fundamental point when starting a website. I am not looking for tips or suggestions, just a general consensus on the following questions: How much content do you develop for a site before you launch? Do you spend weeks, or months, developing content before you go live? Or do you launch the site with the main page only, and then develop content? If you have done both, which method works better in your experience?
I think the amount of content you need really depends. Whenever you have something that is useful is the time to launch. If you have a site that is a catalog of different type of birds, having a description of a single bird is probably not enough. If you have an AdSense tips site and you have a killer tip, you might be able to get away with a single page.
like everybody say. content is the king. there are people who are spending 18 hour for his web site. and there are also people who are spending 1 hour or less for his web site. i think it chages according your expect.
It also depends on what you mean by "launch". You should always put your content up on the web as you produce it to allow Google to start indexing it. When you start promoting that content is a different question.
If it's a content site, I would get it out there as soon as possible. Get the homepage indexed asap so Google's age penalty can start ticking away and add content as quickly as possible. I don't see any benefit in waiting. Just my two cents.
tlainevool has very good point, put your site up as soon as possible so that search engines have time to index it. Once you have added content, put adsense on it.