I have a site that is www.domain.com/main/ the /main/ is where a cms is and when you visit the site your redirect to it. Itís been like this for half a year now and I want to move it to down so the /main/ is not there any more.
I was wondering if itís beneficial to do this or not (seo purposes) or if I should keep it how it is.
I wouldn't have thought this change will effect you in any negative way. It may have an effect if the directory name it resides in currently is a key word or phrase that people search for to find you, but if it is just "main" it shouldn't have much, if any effect.
On a side note, remember to implement a redirect on the "main" directory so those who have that directory bookmarked will still get to the right place.
Yes I would say implement a 301 redirect to direct people to the new page. It will affect most likely the serps since your changing the url although the 301 redirect will help the serps find the new page also.