Accepting guest post's then what points to notice

[frank]

There are no guidelines to do it. But check if it is unique or not, whether or not its been published at any other site. But checking copywright issue isn't enough.

You have to see that how is the post actually. Is it useful or just it has been written just to get a link back. Some webmasters may just suggest you that its is wise to accept an article which is atleast 500 or 1000 words long. But I personally don't think that its the matter. Articles usefulness can't be said by the count of words.