There is not a way to hire a good SEO...

...other than through "who you know." Simply because no SEO company out there wants to give you any real way of testing their claim BEFORE you shell out money. Things like "money back guarantees" are just not reliable / shadey. And of course no SEO is going to disclose his best methods.

Absolutely, you hire an SEO based on track record and or by recomendation.

No genuine reliable SEO would offer you a guarantee because its just not possible.

What an SEO should do is tell you which methods he is going to employ and show how this will bennefit you.

SEO is a process not an event. If some good SEO is done and you continue to build content and links it will be far more valueable in long term ROI than any other form of advertising.

If you are paying a lot of dough then go for a contract with some benchmarks.... 1/4 money in advance... 1/4 after so many links or so high of placment... 1/4 after other benchmarks and 1/4 upon conclusion. This will assure some performance.

This is typically how i do it but i divide even further between off and on page optimization.

While there are alway "shady people" in any industry the simple truth is no single professional will be versed in every area/industry which is a major disadvantage.

I've seen so many client's that absolutely know what phrases they wish to target only to gain lackluster traffic from the #1 results obtained... course the client does not pay for lackluster results regardless of whether they defined to the terms to work with.

SEO isn't a tangible service like having a muffler replace... the out remove, new install and payment for services rendered and they are happy... which SEO if the work is accomplished to the specifications of the client - regardless of benefit, return or ROI was services provided or not?

SEO is risk management a client only gets unlimited "no risk" only when they pay a premium... tying that to the fact that you can indeed be scammed means clients really need to be more accountable for the choices they make... e.g. poor assessment of SEO = the fault lies on your end.

Without being able to analyze a track record, I've been finding that those interested in having their sites optimized turn to other benchmarks. I've written a lot of articles about SEO, and apparently they've been pretty good, because the more I write the more I get email from people wanting me to optimize their sites.

I point these folks to the SEO Professionals forum. It's the least I could do.

I highly recommend SeoMoz.org and seobook.com. Good pricing for a good seo and they are good seo. I am too tied up at the moment to accept new work or I might help you get started.