I just got approved about a week ago, but I haven't put it on my site yet. I still debating whether I should wait until I develop my site some more and get more traffic, or go ahead and put it on.
To have a good planning is good, I totally agree with your decision, Good luck on your Adsense Journey
First account since 2003 (when it started) (this account is obsolete now), second since 27 december 2004 till now.
For about 4 months... I recently changed my page design, and google has not indexed the new pages yet