The application can just be a simple list of questions you want answered, or you can look online for ideas. Make sure it's compliant with fair housing stuff (i.e. no questions you can't ask), but it's mostly up to you what sort of information you want to know based on your rental guidelines.
As far as the lease, I wouldn't get one from a website, because it'll vary so much by location.
Look for a lease that your local association of Realtors uses--they likely have one that's more specific to your state and local laws and has been tested/vetted by lawyers and the courts.
