Bonnie, call your hosting service and ask whether you can add a spf record. Some (like godaddy) definitely allow/encourage it. As for expertise: see
http://old.openspf.org/wizard.html or even
http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/ ;-)
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
