Definitely, Tunisia is a gem in North Africa with its rich history, culture, and beautiful beaches. Here are some details to help you prepare for your journey:

Best Time to Visit:
The most suitable time to visit Tunis, Sousse, and Monastir is during the spring months (April to June) and fall (September and October) when the weather is pleasant for sightseeing.

Route and Accessibility:
Sousse and Monastir are easily accessible from Tunis by trains and buses which are frequent and efficient. Taxis are also a viable option for transportation within the cities.

Altitude and Acclimatization:
Tunisia is primarily at sea level, hence altitude sickness is not a concern here.

Accommodation and Booking:
Hotels, guesthouses, and vacation rentals are abundant in Tunisia. It's always recommended to book your accommodation in advance, especially during the high season.

Clothing and Essentials:
In Tunisia, the dress code is casual but modest, respecting the local traditions. Don't forget to pack sunscreen, hats, and sunglasses as the climate can be hot. A comfortable pair of shoes is important as there can be quite a bit of walking involved in sightseeing.

Health and Safety:
Ensure you're fully vaccinated before your travel. Avoid drinking tap water and rely mostly on bottled water, as the tap water might upset your stomach.

Local Etiquette and Respect:
Tunisians are very respectful and hospitable. When visiting mosques, ensure you dress modestly. It's common to haggle when shopping in local markets.
In Tunisia, tipping is a common practice, so always have some spare change ready.