You can browse my new page on TripAdvisor, read some reviews left by other travellers, and if you travelled with me before, would be awesome if you leave a review yourself!
In case I’m not available, I can highly recommend my collegue Nadav Jakob.
Official Tourism Board Website: https://www.visitberlin.de/en
Free Advice Berlin, a friendly and helpful facebook group: https://www.facebook.com/freeadviceberlin/
ResidentAdvisor, clubber’s best friend: https://www.residentadvisor.net/guide/de/berlin