Pros: The city is very clean, safe, people is friendly, lot to do
The city is one of the most important in Mexico, like the other review says, many things happened in this city.
As a tourist you will know only the historic district, but the city is much more bigger than what you may think.
Arriving to Queretaro is easy, by plane the city has two airports, one small for local flights, and another intercontinental, the second is used only for imports/exports but eventually they will have flights to US. By bus you can get it from Mexico City, or from the frontier, the buses are so much better than the US buses, there are no chickens, and donkeys in the buses, and the bus station is like an airport.
While you are in the bus, before arrive, check the road, when you pass the toll you will see that the road change color from black to white, is beautiful, nice, just like in the states, that is when you enter the state of Queretaro, they have (in the state) really good roads and streets. Recently they have trouble with rains (too much water) and the flow destroy all the streets so you will see (if you go in this time) a lot of workers fixing the streets.
When arriving you can visit the historic district, enjoy a soccer game in the stadium "La Corregidora", go to a bull fight in "Plaza de Toros Santa Maria", or enjoy a concert, there are many concerts of mexican an international groups in the city, most of them in the Auditorio Josefa Ortiz, and also enjoy a music concert with the city's orchestra at the Teatro de la Republica (the theater where the constitution of the country where signed).
In the historic district, old town, you will see all kind of stuff, like expensive boutiques, next to a gorditas store (gorditas like in Taco Bell, but much better).
The places to go are all the plazas or garden in the center, there are a lot of small coffee shops european style, chairs in the street like in Paris, with coffee from mexican states (veracruz and chiapas) and from all around the world. If you are looking for a Starbucks, there is none of them, so you can go to the Italian Coffee Company is just like Starbucks.
Visiting museums is very interesting, the Art museum has a big collections of paintings from the 1500's to the 2000's, there are also great art galleries, some of them with a coffee service and live music, in Andador Libertad there is Galeria Libertad, and also Quadros Cafe and Galeria.
In theater the city has a lot of small theaters, and some big ones, like the Teatro del Seguro with plays all the year.
In the gardens at night there are free plays for all the people, made by independents, or students of art, there is also free concerts and shows in the gardens, from clowns show to a really weird play, capoeira demostrations, african music, and more, in the weekends, just walk in the crowded night and you will see some of them. All of this in week ends, which in Queretaro is Thursday night, friday night and saturday night, they like to party. And sundays they spend the day with family and go to one of the many churches (catholic).
In the sundays in the morning in the garden called, Plaza Guerrero, there is an art gallery on the plaza, and the artist are there selling their work, you will find something for everybody.
For those who love shopping the city has several malls, for all kind of people, if you want to buy cheap but nice, go to Plaza de las Americas, if you want to spend time, shop a little, eat, watch a movie, affordable enough, go to Plaza del Parque, if you are fashion style, like expensive stuff, look for brands, go to Plaza Boulevares or Galerias Queretaro Liverpool.
Also there are many cinemas, so you can catch the movies, and maybe watch them in spanish (Mexicans prefer subtitles). The big hit movies have a premier at the same time than in the US, so you won't lose that big movie you wanted to see. If someone tells you to go to Multicinemas is referin to Plaza del Parque movie theatre.
For the lovers of nightlife, I had visited almost 30 night clubs and there are more, Mexicans are very fashionable, so if a night club is out, it closes and reopens with new name and concept, in a matter of months. I recommend 4Play (Foreplay), Mumbay Club, Metro Club, La Catrina, El Purgatorio, El Columpio and for latin music only, Mambo Cafe.
In restaurants you will see real mexican food, and no matter what everybody tells you, you can eat in the street, is tasty and cheap, the only rule is, go with someone who knows, and only to those with a lot of people (that means is safe). About Montezumas Revenge, is a myth.
In the city main square, where is all the thing I said to you, you can walk (if you have condition to do so), or take public tranportation, the cabs are yellow like in NY, and are very safe, there are a lot of taxis.
The city is formed by three countys, or municipalities (three mayors have influence in the city), and the main is Santiago de Queretaro, which is divided in six delegations.
If you don't leave the main square of the city, which is surrounded by the avenues called 5 de Febrero and Bernardo Quintana, you will never get lost, and you can walk almost everywhere, you may get tired.
In march 21st the city and surroundings are a point of meeting to receive the spring, from the city (30 min) you will see the Pe?a de Bernal the third largest rock in the world, there hundreds of thousands of people reunite to receive the energy of sun equinox, and in the city there is a pyramid called "El cerrito" there too the people go to receive energy, there are thousands of people too.
The city is the second city with the largest GDP in the country, the cops are very nice and helpful, there are 3 kinds of cops, the transit cops; which controls traffic rules, the Guardia Municipal; traditional cops who arrest people, and the State cops; which do the two things, transit and criminals. The city cops are in Mercedes Benz cars, and in the historic district they ride bicycles and golf cars.
The city has more than 25 universities, some of them small like 500 students, or other with 20,000 students
I made this review to complement the other review.
UPDATE: Queretaro Interconntinetal Airport now offers flights to/from San Antonio, Tx using the mexican AeroMar