Got sky installed today only thing getting on screen is "no video signal"
Sounds like the "channel" you are trying to watch on is not the one it's plugged into, or a faulty lead.
check the connection from the sky box to the tv, and select the av or hdmi channel that it is plugged into on the tv.
check the lead by swapping it for a known good one, for example from a dvd or ps3, but unplug from the dvd/ps3 and plug into the sky box(make sure that all the units are powered off when swapping leads) and try on the channel you normally watch/use the dvd/ps3.
If you suspect the sky is at fault, press menu on the sky remote and then flick through all the av/hdmi channels until you find the menu, then try to reinstall/retune the sky box.
If that don't work phone sky......................