Sure! These are beautiful and historical places to visit. Here are some tips to make your journey smooth:

Best Time to Visit:
The best time to visit these places is during spring (April to June) or in fall (September and October) when the temperature is mild and parks are green and blooming. December can also be a magical time with festive Christmas markets and decorations everywhere.

Route and Accessibility:
All three places are well-connected by train with London. You can reach Cambridge in about an hour and Norwich in two hours from London. It is highly recommended to use public transport in these cities due to traffic situations and expensive parking.

Altitude and Acclimatization:
The altitude of these cities is not high, therefore, acclimatizing is not a concern.

Accommodation and Booking:
Bookings should be made in advance to avoid any kind of inconvenience, especially during the summer and Christmas time, when they're crowded with tourists. There's a range of accommodations to suit different budgets from luxury hotels, quaint B&Bs to budget hostels.

Clothing and Essentials:
Pack according to the season. Summers are pleasant but a light jacket can be helpful during the evenings. In winters, warm clothes are necessary as it can get chilly in the evenings. Always carry an umbrella or raincoat, as sudden showers are common.

Health and Safety:
The cities are generally safe, but common sense should be used, especially in crowded tourist areas. Do purchase travel insurance before travelling.

Local Etiquette and Respect:
London, Cambridge and Norwich are cosmopolitan cities, still polite etiquette is appreciated. Keep to the right on escalators. When visiting places of worship or high-end restaurants, dressing smartly is preferred.

Remember to always discard your litter in public places, as the locals are quite particular about cleanliness of their cities.