I don't know if there are still tickets. You have to call them: Hotline/ Tickets
And Hotel, I'm not from Berlin, so I can't help you there. I rent a little apartment a few month ago. And this is only 2 or 3 minutes away from the Courts away.
Something like this you can find here: Apartments
Maybe i am going too, is there a good hotel near the tenniscourt?
Are there still tickets available at the tournament days, or should I buy them now?
Thanks for helping me...
you can buy the tickets there, no need for ordering them beforehand.
and with hotels, look up the usual booking places, berlin is quite cheap with hotels, because we have to much or just stay at the youth hostel in wannsee. it's a 10min trip by train from there. or try hostels.com, anthing in western Berlin, like Charlottenburg or Wilmersdorf will be fine. it's pretty easy to get to the courts, because they are located near the local train station Grunewald.