SPF records CAN help, but, they do have some issues along with it that make them a little difficult. I've seen spammers avoid domains that have SPF records because the major mailbox companies (gmail, hotmail, yahoo, etc) will drop mail instantly if the SPF record isn't set.
The potential issue you have is that you may need to change the way you send email a little, or, you might face having a 'permissable sender' list that is not going to be restrictive enough.
Or, you may run across spammers that don't care/don't check and they use it anyhow.
http://www.openspf.org/