Sharon's school system always comes out highly rated in state surveys and has a very good reputation. Take a look at the link provided by my colleague below. You can also look at the State Dept. of Education rankings which will give you test scores. The schools are well supported by the people in the town and by their property taxes.
You may also want to take a look at the Sharon School Dept. website, see if you can call and talk to the superintendent or visit one of the elementary schools to give you a real feel for what it is like there. Everyone values different qualities in a school district so what is important to one person may not be important to another.... more
Given that there is only one high school in Sharon, if you buy this condo and you and your child live there as your primary residence, then yes, your child should be able to attend Sharon High School. Most towns have pretty strict residency requirements. Your best bet is to talk to the school department directly. Here is the website for the Sharon public schools: http://www.sharon.k12.ma.us/pages/Sharon_Public_Schools