I was at the website Producer Founder and came across these two blog post on finding an agent. The firsts one is called 3 Things to Prepare Before Calling a Hollywood Agent. Very common sense things. First and foremost a great script. As I have said in the past 80% of good film is the script. Them after that is doing your research on actors and then figuring out what you can afford to pay them.
Then the second blog post, How to Talk to Agents About Your Movie, is about contacting agents and how you should go about doing that. It is common sense, be professional and be nice. Don’t be pushy and don’t waist their time. If you get a no from them, move on.
I hope this helps.