1) Can I just create one code from adsense, and place it at the end of all of my posts. Or do I have to create a new code for every post? 2) Can I put the section start/end codes at the beginning/end of each post, so the adsense placed at the end of my post will be relevant to that specific post? Or does it not work like that, since there will be 3 posts per page...
1. Yes, you can reuse the codes for any parts of your site. 2. There's also a code for that where you can specify the content for ads relevancy. I forgot what it is because I seldom use it. Just search google for it.
1) yes thats how we can use that or else it will be lot of waste of time to create new code for each new site 2) yes using some plugins you can implement that within 3 posts limit
When I try to reuse the same code sometimes it either takes longer to display or it never displays so I just create a new one each time for quickness.