Here by chance.
As for the delay it will range between about 4 minutes when Mars is at Opposition to about 24 minutes. And there will be about a month a year when mars is behind the Sun (at Conjunction) where you would not have any communications.
Of course from Mars it would be that Earth is at Inferior Conjunction (Closest) and Superior Conjunction when it is behind the Sun.
(Opposition is when an object is directly oposite the sun and therefore the closest to the Earth)
Actually Saturn is at Opposition this right around now, and the rings are wide open so if you know someone with a Telescope go take a look.