Members' tickets can be bought from 16 March (depending on cinema) with public booking starting a week or so later. Check the Picturehouse site for a full list of booking dates by location.
Prices are: Live screenings £30, Encore screenings £20, with £7 off each price for members. Annual membership cost varies; in London it's typically £40, and includes 3 free tickets for standard shows (not including Met Live and similar events).
Even with the members' discount Picturehouse is not quite the cheapest deal in London (see here for alternatives), but it still (oddly) costs less than the grant-aided BFI and Barbican, which have not yet announced when they will open for booking.
The Season (Live Shows):
Saturday 11 October, 5.55
Saturday 18 October, 5.55
Mozart’s Le Nozze di Figaro – New Production
Saturday 1 November, 4.55
Saturday 15 November, 5.55
Adams’ The Death of Klinghoffer – Met Premiere
Saturday 13 December, 5.00
Wagner’s Die Meistersinger von Nürnberg
Saturday 17 January, 5.55
Lehar’s The Merry Widow – New Production
Saturday 31 January, 5.55
Offenbach’s Les Contes d’Hoffman
Saturday 14 February, 5.30
Tchaikovsky’s Iolanta + Bartok’s Duke Bluebeard’s Castle – New Production
Saturday 14 March, 4.55
Rossini’s La Donna del Lago – Met Premiere
Saturday 25 April, 5.30
Mascagni’s Cavalleria Rusticana + Leoncavallo’s Pagliacci – New Production