Question with redirection plug in

I think I did some things wrong the first time I was using the redirection plug in. I’m not sure what did, but I was having lots of problems with people getting errors. So I disabled the plugin. Now I have reinstalled it, and cleaned out all of the old data, and have slowly been fixing some 404’s that I have.

I wanted to be sure I am using it correctly, and setting up the options correctly.

Under URL monitoring I have post and page urls set to modified posts, and the box labeled “monitor new posts” is unchecked. What does checking that box do? And do you suggest doing it?

One thing I have been doing is redirecting all of my pages without a trailing / to the page with the slash. For some reason google webmaster tools was showing duplicates. http://noahsdad.com was showing up and so was http://noahsdad.com/. So I have been going through and redirecting every page that I am seeing duplicated. So http://noahsdad.com redirects to http://noahsdad.com/

I’m not sure if that is ok, or if there is a better way to do this. I just don’t’ want google thinking I have 2 different pages.

I’d appreciate any feedback or suggestions.

Thanks.