Developing A PDF iPad App

I need to develop an app for the iPad that acts as a PDF Viewer. It needs to have a homescreen that allows the end user to select the PDF wanted and open it. Once the file has opened it needs to be able to scroll through all pages and the *** points must work. It also needs to have a search bar that allows you to search for the *** points and different text within the PDF.

I have absolutley no idea of how to approach this so looking for advice, I know it would be easier to just download a PDF reader app but i need to make this my own! Thanks in advance and hope that someone out there will know how to approach this!