Social Media marketing & SEO

My company has developed an eLearning course. We have a landing page, a sales page and an email list set up to populate. We are trying to create a plan to do a facebook, twitter and google marketing campaign but I am stuck with trying to figure out how much to spend on each (how much is reasonable for a month-long campaign on each, and what I could expect in terms of conversion rates), and what to do to target our audience. I can make the ads myself (I am a graphic designer) so I don't need that.
So I'm looking for someone who could help with conversion metrics, SEO for our landing page, and an ad plan that details the spend and what we can expect to achieve in terms of conversion, and how to measure the metrics.