I know Chris Henderson covered this topic in depth on my blog awhile back, but how to find actors is a question I get asked over and over. While it is not an expensive process, it will take a bit of time and effort to line up all of your ducks and get people interested in your project enough to want to work with you. If you already have a reputation, this might be easy. If you don't, you've got your work cut out for you.
Either way, I hope this video helps in your pre-production process.
Collection Day Audition Notice (designed by Stephanie Stephens)
Collection Day Audition Sides (attached as notes to the CD Facebook page)
Directing Actors by Judith Weston
Chris Henderson's series on "Casting Your Microbudget Film"
Thumbnail photo courtesy Morguefile.com
P.S. Don't forget to be professional during auditions. Actors (like crew) are doing you a huge favor. Treat them with the respect and professionalism they deserve, whether they are good for the part or not. This is where you will begin building a reputation with the local filmmaking community, and everyone talks. Give them good things to say and you'll always have the talent you need.