Remember - your course texts already provide you with a bunch of great resources to start with!
You will likely want to include some contemporary literary criticism and book reviews in your presentation. These sources will help you.
Many of these databases also include biographical information and contemporary reviews! (You will likely notice the duplication.)
Did you know that the library offers streaming video? You can even create clips and embed them into your PowerPoint presentations! And there is definitely stuff on the Brontes!
Here is a list of websites that have background and historical information about the Brontes that may help you to get started. Beware, however! These sources would not likely be considered scholarly. Use with caution.