Blogger Comments are not shown on the Main Page of the blog. This is because the Main Page contains many posts and adding comments also to them would make it very long and slower to load. Hence there is a COMMENTS link below each post which when clicked on brings up the comments page in a pop up window. You can enable this in Settings--->Comments---->Show comments in a popup window?---->Yes----->Save. Otherwise the comments page will replace your blog page when the COMMENTS LINK is clicked on.
The comments page cannot be customized with the same style as the rest of your blog.
To enable Blogger Comments :
1. Go to Settings----->Comments----->Comments----->Show.
2. When creating a post in the Post Editor click the 'Post Options' link in the bottom frame. The bottom frame of the editor will expand to show the Reader comment options and you can select whether to allow comments for that post.
3. Click on Layout on Dashboard and then on Edit link in the Blog Posts widget. In the popup window check the box for comments and save.
When posting a comment on other blogs offer constructive comments and try not to paste in links to your blog or you may be characterized as a spammer. Also spellcheck your comments and make sure of the grammer. The language should be polite or your comment may be rejected/deleted by the blog owner. Do not abuse third parties in your comments.
REPLYING TO COMMENTS
Always reply promptly to comments made on your blog. To reply just click on Post comments link and post your own comment. Again the language should be polite and non-abusive. Enable comment moderation in Settings---->Comments so you can reject comments by abusive persons. Do not publish abusive comments. Just ignore them and the trolls will go away!
COMMENT RESPONSE NOTIFICATION
You cam keep track of who is responding to the comments you make on other blogs using http://co.mments.com/conversations.
UPDATE : Blogger has now enabled comment response notification which sends you email as soon as someone posts a comment below yours.
To delete a comment click on the Trash Can icon below it on the comments page. After deleting it once a message that the Blog Administrator has deleted this comment will be shown in place of the comment. To delete this message also click the Trash Can once more. You can also check the box 'To remove comment forever'.
CANNOT EDIT COMMENTS
Comments cannot be edited or else they would be open to manipulation. You can only accept them or reject them in totality or choose not to publish them.
If you think you may have made the wrong comment you can delete it and make a fresh comment with an altered content. You can include links in your comments but not images.
PROFILE IMAGE ON COMMENTS
To show your profile image in your comment you should upload a profile image via your Edit Profile page Photo URL box (Click Edit Profile link on Dashboard). Also the blog you comment on should have the Display Profile image enabled in it;s Settings----->Comments.
Comments can also be seen via Comment Feeds. The comment feed for your blog is :
Replace MYBLOG with actual blog name and 'TYPE' with 'Short', 'Full' or 'Default'.
Comment Feed URL for a particular post is :
Replace 'THISPOSTID' with the postID number. To get the postID Number of a post load the post in browser by clicking on it's title. Then click View---->Page Source in browser menu. Search for 'postID' in the Page Source.
COMMENTS MAILING LIST
If you want blog comments to be sent to all blog members you can create a Google Group and add your members to it. Then copy and paste the email address of your Group in Settings---->Comments------>Comment Notification.
Comments on Main Page.
Notification of Response to Comments.
Background Color to Comments.
Comment Form Under Posts.