I rent out a guest room (20sqm) in my apt (100sqm). I live in the apt. permanently. There is als a living room with balcony, a bathroom with tub and a kitchen. You will sleep on my sleeping couch which is very 160 x 200 cm large and very comfy. I will hand out towels and everything you need. So should you have any questions just contact me. My apt is in the middle of everything in the Wrangelkiez Kreuzberg. Very close to the bus (less than 1 minute) and to Schlesisches Tor U-Bahn (3 min. walk).
Wrangelkiez is awesome ;)
There is a bus stop in front of the house. There is the U1 going at Schlesisches Tor which is a 3 minute walk. There is also the S-Bahn Warschauer Str. which is a 10 minute walk.