To be honest, a lot of what passes for SEO involves a lot of smoke and mirrors. People will call and email you saying they can get you on the first page of Google search results. In many cases the claims are likely true, because anyone can do it. Optimizing your site for Google isn't about learning a lot of secret tricks as much as it is about using common sense and making sure you have relevant and unique content on your site. Thinking you need to optimize your site? Ready to start today?
Do you know how much traffic you're getting now? Do you know which search terms are driving visitors to your site? Which are your most popular pages? Which are the least popular? How often does the Googlebot visit your web site?
You don't know? In that case, what you shouldn't be doing is optimizing your site. What you should be doing is analyzing your site traffic. If you're going to increase your site traffic, you'll never know if it's working until you know your current traffic patterns. Don't pay some guy thousands of dollars to increase your traffic if you don't know how much traffic you're currently getting. It's a fool's errand. He can tell you you're getting twice as much traffic and you'll never be able to verify it.
Before you do any kind of work on your site, get yourself set up with a good web site traffic analysis tool. The WunderCounter can give you all the information you need to arm yourself with before spending the time and/or money on optimizing your site. There are also a number of other services you can use to analyze your site traffic. The main thing is to be fully informed before you go making changes. You should also be aware that, by making a lot of changes, you may actually decrease the amount of traffic you're getting, so you should have a way of measuring that so that you can protect yourself and be able to reverse bad choices.
So, basically what I'm trying to say is that any meaningful set of measurements requires a baseline to measure against. If you optimize before setting your baseline, many of your measurements will largely be meaningless.