Sure, visiting Guwahati, Shillong, and Cherrapunji can be an exciting experience. Here are some travel tips to help you in your journey:

Best Time to Visit:
The ideal time to visit these places is during the post-monsoon and winter seasons, between September to April. The climate is pleasant and is great for sightseeing.

Route and Accessibility:
The journey generally starts from Guwahati, from where Shillong is 100 km (approximately 3 hours drive) away. From Shillong, Cherrapunji is approximately a 2 hours' drive. Taxis or rental cars are easily available.

Altitude and Acclimatization:
Acclimatization wouldn't be much of an issue as these places are not at very high altitudes. However, do take time to rest after your journey reach.

Accommodation and Booking:
There are numerous hotels and guest houses available in all the places. Make sure to book your accommodation in advance, especially during peak tourist seasons.

Clothing and Essentials:
Pack light cotton clothes if you're visiting in the warmer months and warm woolens if you're visiting during winter. Comfortable shoes are a must as there could be some walking or trekking involved.

Health and Safety:
Always carry basic first aid along with you. Check the travel advisories for the region before your trip.

Local Etiquette and Respect:
The locals are very welcoming and friendly. Do respect the local culture, traditions, and ecological sensitivities, especially when you're visiting places like Living Root Bridges in Cherrapunji.