Need to remove widgets? from post pages

I would like to remove the "search" "archives" and "catagories" from the right side of my post pages. I am able to do it with "pages" by selecting "long" or something like that. Where can I go to do this...editor?

Also need to remove "Posted on 25th January 2013 in Main Content by admin" above the posts...thank you. You all have been very helpful

 

1.For your first issue

Go to blog.php present in your theme directory and remove the code given below

Code:

 <?php get_sidebar(); ?>

Sending image for reference



2.For your second issue

Paste this code in Custom CSS
Appearance > Theme Option > Styling Option > Custom CSS

Code:

.content_wrapper .side_content .post .post_info {
display: none;
}

 

As usual...prompt and great advice. I like posting code in the Styling options as it is easy to see what has been done instead of changing the "editor"