For the record, I agree with @Compmom. An Ivy League school will not automatically be the best in your field so make sure to research all your choices. Work with the grad school advisor(s) at your school to identify appropriate target schools and strategies for applying. Most schools will work with alumni even years after graduation so they can be a great resource.
Another resource is alumni working in the field you want to pursue. See if your school has a shadowing program that will hook you up with alumni. Not only can it be helpful in the short run, but it can help you increase your contacts in the field.