Los Angeles - How to screen a tenant

I'm a new landlord and have recently bought a condo as a rental.

I have no experience processing rental application and am wondering how should I start? what is the first steps Ishould do.

Where can I find the rental application form. Is it free?
How and at what point do I ask them to show paystubs and bank statements. Is this normal to ask will everyone really show. This is so sensitive information and I'm wondering if they will really show it to me.

I really need help on links to the application form.

Thanks.