The first step in the process of most practitioners of search engine optimization is keyword research. This is often an iterative process in which the site owner and presumably industry expert works together with an SEO in order to determine which keywords and phrases to target for high rankings. Although to many this would seem like a very introductory level topic, the fact is that keyword research can make or break a campaign when it comes to determining actual success. Choosing the right keywords will lead to rankings that produce legitimate traffic, as opposed to rankings for terms that may have lots of "competition," but little "action."
A few threads going on at various forums currently are discussing keyword research. At High Rankings Forums, a member complains of - yes I know - high rankings in Google and Yahoo!, but no traffic. A couple of good recommendations follow.
At Search Engine Watch Forums, an interesting discussion about measuring keyword competition is happening, with the conversation seemingly helping to dispel some myths about degree of difficulty estimation. One of the classic discussions on keyword competitiveness can be found at the HighRankings Forum's Keyword Research category. A recent thread at Cre8asite Forums discusses the concept/alleged importance of keyword density.
Not sure if you are targeting the right keywords for your SEO initiative? Check out any of the above threads. If you know of more good ones, feel free to post them in the comments.