Lacey, we always welcome questions here on Trulia.com, especially if there is a business opportunity attached to it. The Realtors are a fairly tight knit community. If you are working under an exclusive Buyer representation with another Realtor, then we (collectively) can not solicit your business. There are standards of practice (i.e. our Code of Ethics) that we abide by every day and help us to avoid conflicts. You will receive many responses to your question, and sometimes you will receive the same information from many agents whose intention is to solicit business from you, as you have seen with your previous question earlier today. However, this is a slippery slope for all of us since you are already represented by a Realtor.
Dixon has provided a very good resource for you below with the "greatschools" website. But once again, as Lynn suggests, the best way for you to get information is through the Realtor and/or agency that represents you. They have a fiduciary obligation to assist you. If that doesn't work out, then you may have the opportunity to chose another Realtor/agency to represent you.
That being said, the Dallas Ft Worth metroplex has many great schools, especially in suburbs north of Dallas as you have indicated. Many of us reside in these areas and can speak directly to the quality of education that our children are receiving at various levels. Look for "exemplary" schools which are the highest rated by the Texas Education Agency http://www.tea.state.tx.us/