Extensive keyword research is the first step to any search marketing campaign. Keyword research is the framework on which your entire campaign is built, whether you’re using search engine optimization, pay-per-click advertising, or both. If you don’t get your keywords right, your efforts will be wasted.

If you’ve started on the wrong foot, there’s still time. Good keyword research is an evolution. The world of search is constantly changing, and your keywords should, too. The terms that people are using today may not be the most successful six months from now.

Whether you’re putting together your first keyword list or adapting your current list, here are some tips to get you started.

Don’t use the same keyword list for your SEO and PPC campaigns.

SEO and PPC are complete different, and they require different keyword lists. In fact, most of the keywords you use for SEO probably won’t even end up on your PPC list. PPC keyword lists are highly targeted — you’re looking for keywords that will target a very specific audience to ensure you’re not spending money on clicks from tire-kickers. For SEO, your keywords should be relevant, but much broader to reach a larger search audience.

Never build a keyword list based on assumptions.

No matter how well you know your target audience, the truth is that as a business owner you think differently than your consumers. Many marketers and business owners create keyword lists based on their knowledge of the business instead of search volume. They’re surprised to discover that consumers are searching for a completely different list of terms. Your technical knowledge may be preventing you from finding the laymen’s terms for which your customers are searching. While a good knowledge of the terminology in your business is a great place to start your research, you need metrics to back you up. Use a keyword research program like Keyword Discovery or WordTracker, Google AdWords’ Keyword Tool to ensure that the keywords are the right ones.

Break long keyword phrases into pieces.

For SEO, try breaking your keyword phrases into smaller pieces to maximize your reach. For example, while “new houses for sale” may have a decent search volume, you might have better results with something like “new home listings,” because it works as a stand-alone keyword phrase, two separate shorter phrases (new home and home listings), and home has a higher search volume than houses. Create power phrases by ensuring that each and every word in your keyword phrase packs a punch.

Choose your keywords wisely.

Once you’ve built a long list of potential keywords, it’s decision time. For PPC, you can test a long list of keywords to find the most successful. For SEO, you need to be a little more selective. The most successful optimizations use a very short list of keywords — no more than 3 for each page. Don’t just choose the keywords with the highest search volume. Look deeper to create longer keyword phrases that will garner search volume without being too competitive. Find a balance between search volume, competition, and relevance.

Constantly update your keywords based on analytics, conversions, and traffic.

Good keyword research can create a pretty powerful initial list, but you’re not finished. You need to make constant adjustments. With PPC, the changes will most likely be daily, especially in the beginning. Watch your click-through rates and conversions to ensure that your keywords are driving relevant traffic without costing too much, and keep an eye on your analytics to find negative keywords.

SEO is a long-term process, so you’ll want to give your site some time to collect data before making changes. Monitor your analytics constantly to determine which keywords are driving the most traffic to your site. If you’re not getting the results you wanted after a month or two, it may be time to make some changes, shift your focus, or find new keywords.

Usability is one of the most important (and often overlooked) elements of search engine optimization. If your website is designed for the end user, you’ll reap the benefits in your search engine rankings and your customers will be more likely to interact with your website in the way that you desire.

Keep these usability best practices in mind as you design your website to ensure a good user experience and better search engine results:

Navigation

• Include a clear navigation bar that links to every page on your website and appears consistently on each page.
• Link to pages on your website internally throughout the copy using relevant, keyword-rich anchor text.
• Use breadcrumbs to show users where they are and where they came from.

Accessibility

• File sizes for your pages should ideally be smaller than 200KB to optimize loading time and search engine crawling.
• Place copy in the first 100KB to ensure that your keyword-rich content is being crawled and indexed.
• Keep pages as close to the root as possible. Users and search engines should be able to reach each page on your site from the homepage in two clicks or less.
• Utilize permanent 301 redirects for known deleted pages to land users on a similar page and maintain links.
• Use a custom 404 page to redirect users and search engines that have reached a page that no longer exists on your site back to the most useful content on your site.

Readability

• Don’t use fancy fonts for your body copy. Simple fonts, preferably sans serif, are easiest on the eyes and most likely to display properly on all browsers.
• Write clear, concise content for each page. Web users get overwhelmed with huge blocks of text, so limit the amount of text on each page.
• Break up large blocks of text into bite-sized pieces with headers.

Simplicity

• Keep your on-page code as clean as possible by moving JavaScript and style sheets into external files.
• Use animation and Flash sparingly. Too much animation can be distracting for users, and while search engines are getting better at indexing Flash, it’s not perfect yet.

Optimization

• Focus on one page at a time in your optimization, and optimize it for no more than three highly relevant keywords. This will tell users and search engines what the page is about quickly and easily.

Finally, be sure to test run usability tests with several user types likely to visit your site to catch problems that normal users may encounter. Be sure to run tests on all of the major browsers (Internet Explorer 7 & 8, Firefox, and Safari). What works on one browser may not work on another.