Look for daycares, schools and training centers that use Montessori methods. Here's alittle info for more go to montessori.edu

"Montessori is not a system for training children in academic studies; nor is it a label to be put on educational materials. It is a revolutionary method of observing and supporting the natural development of children. Montessori educational practice helps children develop creativity, problem solving, critical thinking and time-management skills, to contribute to society and the environment, and to become fulfilled persons in their particular time and place on Earth. The basis of Montessori practice in the classroom is respected individual choice of research and work, and uninterrupted concentration rather than group lessons led by an adult. Group lessons are seldom found in a Montessori classroom, but learning abounds. As you read through these pages you will discover the unique practices that make Montessori the fastest growing and most successful method of education today. "

Depends on where you live, your needs, your preferences and your child's readiness for preschool. In the UK children can start nurseries/pre-schools as soon as they are 2 years old and many accept children still in nappies as well. Some children start aged 3 as some parents prefer to wait until the year before they start Primary school. I would advise you to look around find a nursery/pre-school you like, register your daughter and ask them about the admissions crieteria then start your daughter there as early as possible and find out there other policies such as being toilet trained and so on. The younger children begin there education the better! So if she can start at 2 great if it's 3 that's good should definetly start before she is 4 though.