Time Out (http://www.timeout.co.uk) is a weekly magazine (every Tuesday) that gives you all the information for cinema, theatre, opera, exhibitions, events… in London.
You can also find information for the cinema showings at:
Odeon (http://www.odeon.co.uk/)
LondonNet (http://www.londonnet.co.uk/cinema/index.html)
Curzon Cinemas (http://www.curzoncinemas.com/)
And if after the cinema you want to go dancing, you will find addresses here: http://www.viewlondon.co.uk/night_finder.asp