How can I add or delete the front page's blocks?
1)First of all create a tpl file "page--front.tpl.php".

2)Suppose you want to place block  in sidebar second region use devel module to see the content of your page.


&lt;?php dpm($page);
dpm($page['sidebar_second']);?&gt;


3) Write following code after executing above code:

&lt;?php print render($page['sidebar_second']['id_of_your_block']) ?&gt;


for deleting/hide the front page block 

1)Go to edit page at block/region setting/none