I have analyzed so many blogs and find one major issue that in blog we are showing first 10 post with full content on the main page, it mean we have 4 URL's for a single post. One home page, second URL with category, third URL with lable, fourth URL with date etc so it means same content is showing on 4 different URL's. Please help me to resolve it..
The problem you describe rajeshth02 is common, perhaps even expected, and so I'd like to think Google is also aware of this and takes it into account. They want to show the best results after all.
The situation you describe does NOT suggest you need to use the rel="canonical" tag and there are some things you can do to make things a little better if you are worried.
- Write an Excerpt with each post, this will be used along with the title anywhere you display a snippet of your posts.
If your wordpress install doesn't include excerpts as meta descriptions you can add a plugin called "Add Meta Tags". these same descriptions will appear on the index and category pages but NOT on the actual article pages. This will help your articles rank for the keywords on them a little better and cut down on article duplicates.
I wouldn't worry about the category pages too much, some people apply a noindex meta tag to categories but I'm pretty sure Google knows what a category page is, especially if you're using the rel="next" and rel="prev" tags correctly (highly recommended).
The Index page is tricky, you can show excerpts to encourage people to click on "read more" type links into your content or, like it sounds here, you can show full posts which compete with article for as long as the article remains on the home page.
My advice for the homepage depends on how often you post new articles. If you post at least one and usually more articles per day then the articles fall off the homepage fairly quickly which is fine. If you don't update frequently then I'd recommend using snippets instead of full articles on the homepage because you don't want articles "blocked" for very long and you probably don't have a lot of daily followers who appreciate all new content on one page.
tip: add a couple of periods to the end of a url if you use wordpress. If you find that "example.com/some-page" is the same content as "example.com/some-page.." then you probably have many more versions of a page than you think. THAT's when you need to consider a canonical tag and redirects.
Its possible to cause thousands of canonicals even on a static page. Choose your wordpress url format wisely and then link to that format for all external and internal links. Link weight will then determine the true page and internal structure.