Where do I start with Split Test Monkey?

This actually depends on the goal of your page...

We all know it's good marketing practice that a single page should have a specific, singular goal with a desired result, but what that result is, is really up to you.  It could be an email opt-in, a product sale or an affiliate link click etc.

What We Test And Why:  The most important factor is always the offer itself. (This is what you're providing to the visitor) The offer is the most important consideration in the mind of your visitor. What solution are you providing?

FIRST : Test any element that could make your offer more compelling or elements that explain why you provide the solution your visitors are looking for.

Q:  Can you add more persuasive elements to your page to increase the desire for your solution?
A:  ALWAYS!

When you get the offer right you're 50% of the way to achieving your desired goal!

SECONDLY: (and also HUGELY important) is your Headline. 

Testing headlines can have dramatic results. The right headline can deliver 200%, 300% and in some of our tests even 500% increases in conversion rate. So test your headlines (especially on landing pages and sales pages) and ensure you're using good sales copy practices.

Combine a great headline with a great offer and you're practically guaranteed to achieve your page goal.

Beyond these two key elements we're entering "testing geek" territory: Font styles, images, page or background colors, buy buttons, using credit card icons, guarantee seals, calls to action, sub headlines, bullets and post scripts, pop-ups and more... And while each can impact your conversions rate (thus worthy of testing), changes here generally produce only minor improvements.  For instance an alternative style or color buy button style may deliver a 5% lift in conversion. But your main priority should be far bigger lifts. So make these test once you have the big ones in the bag (the offer, the headline).