Hi! It's terrific to know that you're planning a trip to Hamburg, Bremen, and Kiel. These are beautiful German cities with lots to offer.

Best Time to Visit:
The best time to visit these cities is during the late spring or early fall, especially between May and September. The weather is most pleasant and the cities host various outdoor events during this period.

Route and Accessibility:
All three cities are well connected by Germany's efficient train network. Starting with Hamburg as your first stop, you can easily get to Bremen and Kiel by train within 1-2 hours. All the cities are also accessible by car, bus, or plane.

Accommodation and Booking:
Accommodations range from luxury hotels to budget hostels in all three cities. It's recommended to book accommodations well in advance, especially for travel during peak season. Websites such as Booking.com or Airbnb can provide a wide array of options.

Clothing and Essentials:
Pack clothing that you can layer, as weather can be unpredictable. Include a raincoat or umbrella as it can rain anytime. Comfortable shoes are a must for walking around the cities.

Health and Safety:
Germany is generally safe, but like anywhere else, it is always good to stay alert, especially in crowded tourist areas. Remember to check your travel insurance, pack any necessary medications and keep emergency contacts handy.

Local Etiquette and Respect:
Germans appreciate punctuality and politeness. Respect local customs and be aware of silent hours in residential areas. Tipping is customary in restaurants and bars, usually about 10% of the bill.