Hi there,
First off 301 may not be the best for that situation but a tag - rel=canonical sounds like it would be a great fit. You may find the yoast SEO plugin very helpful, if you did want to redirect though there is a great plug in - http://wordpress.org/plugins/redirection/
Now you may be thinking why not a 301? well
author/admin/page/2
category/uncategorized/page/2
as you see the page is under two sections one by the person who wrote it and one under the category the author thinks that page should be. As a 301 is not necessary as it would be confusing (imagine you click on the author but you are redirected to a category!) the canonical tag will point towards the stronger post (lets assume category) and tell Google to ignore the other post as its a duplicate of the category post and give all link juice to that. The bonus of this to a 301 is the post will still maintain its position and the user (or crawler) wont get lost.
The Yoast plugin has the canonical feature I believe (more info here )
Hope that helps if you need more info or i lost you let me know.
More info on the tag is here - https://support.google.com/webmasters/answer/139066?hl=en
and here- http://www.mattcutts.com/blog/canonical-link-tag/