Have you already checked out The Parents Guide to Preschool? It includes information on the academic, social and developmental elements of preschool. http://www.education.com/grade/preschool/

Also, here's an Education.com article debating the merits of academic preschool vs. play-based preschool (http://www.education.com/magazine/article/Ed_Academic_Preschools/), and one about phonics per developmental stage, from infant to school-age (http://www.education.com/reference/article/Ref_Phonics_Whole/)

Good luck with your decision! If you're looking for insight into the choices other parents made and what worked for them:

Our daughter went to a play-based co-op preschool, and she/we really loved it. The school had various play stations (art, dress up, music, climbing structure, etc.) inside and outside that volunteer parents and paid teachers would rotate around throughout the four-hour session. As parents, we'd observe the children at play but wouldn't interfere except for safety measures, answering questions the children had, or helping to mitigate or resolve conflict. There was also circle time where the teachers would read to the children or teach songs, and children always had the option of reading books (with or without adult help) on their own time at their own pace, or they could practice writing or painting, or let their imagination take them wherever it would with the materials before them. Every day at the preschool provided learning (for the children and the volunteers), and once-a-month the parents and teachers would gather (sometimes with guest experts) to discuss academic, social or developmental topics that supported or improved our parenting and helped us bond and thrive as a community. My daughter is in first grade now and has been doing very well in school both academically and socially.

You specifically asked about Zoo Phonics so I will answer your question regarding that curriculum.  As a veteran preschool teacher I can assure you that Zoo Phonics is very appropriate for young children and is a common choice in many preschools across the US.  The reason this curriculum is so popular is because it is considered "multi-sensory" and developmentally appropriate.  The multi-sensory part means that the letters of the alphabet are taught in ways that incorporate sight, sound, and movement, which research has proven is the most effective method to teach young children anything.  The developmentally appropriate part means that it is considered a fun and engaging method of teaching young children.  Many teachers have had great success with Zoo Phonics in preschool classrooms.  

Since you asked for an example of what a typical day in preschool looks like I have included a link below to the schedule for our Title 1, public Pre-Kindergarten program which prepares at-risk students for kindergarten.  You can click the "home" button to look around the site for more details of what each block of time consists of.

As for whether or not it is too academic I think it is important to point out that today's preschool is not the same preschool we attended many years ago, things have changed drastically in the education field since then.  Today, children are expected to enter kindergarten knowing much more than they did even 15-20 years ago.  If a child enters kindergarten already behind it can have a negative effect on the rest of his or her school years.  A child needs to feel positive and confident about school from the get go in order to have a successful school career; the best way to achieve this is to make sure the child is fully prepared for the academics of today's kindergarten.  

Best of luck on your decision!

Vanessa
Pre-K Pages dot com