My test was about half an hour, then an extra 10 minutes going thorugh the forms etc ( I passed!)
I took about 40 hours I think, possibly slightly less. My lessons were in 2 hour chunks but I'd say don't do that as I just got bored and frustrated. Hour or hour and a half lessons are much better. Don't leave it too long either between lessons or you'll displace all the stuff you've learnt.
You should take your Pass-Plus too, cheaper insurance and good fun.
Just a bit of advise, don't do any driving on the day of your test, it'll put you off. Just get lots of sleep, food and drink then you will be better focused. It worked with me!
Good luck!
xxx