Hi @Anonymous User and welcome to the board.
If you "switch on" your NowTV box you should see a floating "NowTV" symbol in green...Press "OK" on your remote control. That will take you to the "Home page" where, down the left, you can scroll down (Down arrow on the remote) to "My Apps". Use the Right Arrow on the remote to go to the Yellow "NowTV" box and press "OK".
That gets you into the secondary page with Entertainment, Sports, etc down the left...Scroll to "Entertainment", press "OK" and you get a page with things like "Recently added", "Featured" and "Leaving Soon" down the left....Now then, right at the top of that list is "Watch Live", press that and it will bring up a "Now and Next" EPG for the live channels available on NowTV.
Scroll about a bit until you find what you are looking for and press "OK". You will probably get a "Rotating Circles" symbol or a circular "Loading" symbol for a second or two but then you should get straight into the programme, in real time. Please note that if the programme starts at 9PM and you tune in at 9.05 PM, you'll have missed the first 5 minutes. That sounds obvious but this "Live" section is not a catch up one, so you can't re-start the programme.
You might be able to on a "Smart" Box, I don't know as I have my trusty black one running.
Anyway, once you get used to it, it gets easier and is just a matter of using the Arrows and OK buttons on your remote and finding the right menu.
Hope that gets you started
Edit: Or you could just follow @4268 's instructions (Beat me to it 
) which are simple than mine! 
