I have no idea with the blogspot blog, with wordpress, I have wrote quick post,. here is the quick link:

http://www.blog.web6.org/with-or-without-www-wordpress-blog/

Thanks!

Kimi.

You can ask me anytime you like :)

Noticed, the post was made in 2009.

Yes, AIO will take care of it, once you installed it, it has an option ↑ “canonical URL” leave it checked. see more: http://www.blog.web6.org/wordpress-set-up-all-in-one-seo-pack-configuration-tutorial/ (number 2).

1. I would not put anything in .htaccess because if you install cache plugin, it can disturb redirection. It is not necessary anway. It is already taken care by your URL settings, see more here: http://www.blog.web6.org/what-to-do-after-installing-wordpress/ (number 9).

2. I would not install any plugins for this.

3. I have no idea about this plugin, i have never tried it, and then i would not install it.

here is a link that explains the plugin above better.

1.If not, what code do i insert into the htaccess.?
2. or to make things easier what plugin can i use to insert a 301 redirect code to guard against duplicate content?
3. what do you think about this plugin?
http://wordpress.org/extend/plugins/canonical/

Actually duplicate content is a myth nowadays, don’t have too much worried about it, just don’t post exactly the same post or pages in your site.

Doing it in webmaster tool is enough, and telling Google to only indexing the preferred domain.

Since editing .htaccess is not recommended, unless you know about it, so i give the easier option in webmaster tool preferred domain settings.

Hope this helps.