Hello! That sounds like an exciting trip you're planning to beautiful Brazil. Here are some tips to make your journey a delight.

Best Time to Visit:
The best time to visit Ouro Preto, Tiradentes, and Petrópolis is during the cooler months from May to September. However, for festivals and cultural events, the period around Easter, especially in Ouro Preto and Tiradentes, is particularly interesting.

Route and Accessibility:
To reach Ouro Preto, you can fly into Belo Horizonte, and then take a bus or taxi to Ouro Preto. Tiradentes is accessible by bus from Sao Paulo, Rio de Janeiro, and Belo Horizonte. Petrópolis is just a short drive from Rio de Janeiro and there are regular bus services available.

Accommodation and Booking:
All three cities offer a wide range of accommodation options. It's recommended to book your accommodations in advance especially during peak months September-May. You can use online platforms like Booking.com, Expedia, etc. for maximum choices.

Clothing and Essentials:
Pack summer clothes if you're going in the warm months but also carry rain protection as showers can be sudden. For the cooler months, layering is advisable as morning and evening can be chilly. Comfortable shoes are a must because you'll be doing a lot of walking especially in hilly areas like Ouro Preto.

Health and Safety:
Brazil is a relatively safe country to travel, but it's always advisable to keep your belongings secured and stay in well-traveled areas. Also, keep your medical insurance information handy and ensure you are up-to-date with routine vaccines.

Local Etiquette and Respect:
Brazilians are known for being warm and friendly. A little basic Portuguese will go a long way to smooth interactions. Remember to respect local customs and religious sites. In Ouro Preto and Tiradentes, which are Unesco World Heritage sites, treat historic structures with care.