I'm a newbie to doing ads, can anybody link to great sources that could help?

you need to see how much you are investing per click on fb,.. I dont think you are paying $5 per lead but it could be as well.

CPA = cost per action (when someone take an action like: submitting their email on an optin-page you get paid some money from the CPA network)
CPC= the classic cost per click (you find this feature in any advertising platform (adwords, facebook, twtter, etc) how much you pay for each click you get on your ad
CPL = the cost per lead (how much you pay for each lead you get)

Its good that your looking at advertising your offer, but you should also know what your customer acquisition number is as well otherwise you could be throwing good money at bad advertising strategies.

Your customer acquisition number doesnt have to be exact but once you know that figure you can then identify which form of advertising is giving you the best return on your investment

For me I like to use this formula as taught to me by my business coach, plug actual or estimated (if you're in the planning stages or just starting out) numbers into the following equation:

(Average Value of a Sale) X (Number of Repeat Transactions) X (Average Retention Time in Months or Years for a Typical Customer)

An easy example would be the lifetime value of a gym member who spends $20 every month for 3 years. The value of that customer would be: $20 X 12 months X 3 years = $720 in total revenue (or $240 per year)

As you can see from this hypothetical example why many gyms offer a free starter membership to help drive traffic. Gym owners know that as long as they spend less than $240 to acquire a new member, the customer will prove profitable in a short amount of time.

What niche is this in?
For your Facebook campaign, how many different ads did you try? How Re you targeting?
Are you tracking what converts for you?