The first step is to is to select moderately competitive keywords. Performing Google research of keywords that you are considering will provide insight to the search levels, value and opportunity of improving your ranking with them. Not all keywords are created equal. Keyword marketing is highly competitive even for highly specialized markets. Those words and phrases that are relevant for your product or service do not all produce the same amount of traffic. Including geo reference, city name, can make help your ranking in local searches quicker.
A short time ago, link building was all that was needed when SEO was simpler. Listings in directories and requesting search engines to index your site was all that was required 10+ years ago. The cost was reflective of the process. Back links are still important but Google evaluates the quality of the links. Just requesting links from anyone and everyone is now detrimental to your SEO efforts. Link building is still the #1 way to get keyword ranking. Now you have to do as much if not more than your competitors.
You've determined the competitive words that your customers use search for your product or services. You've looked at your links. Now review your website to optimize your content to include your keywords, key phrases. Check and improve your page titles, meta descriptions, internal links and more. Then make plans and schedule content additions to be a constant activity performed by you, staff member or valued vendor. Professionals who understand optimization, the competition and opportunities to improve and maintaining web presence is worth their weight in gold when it comes to leveraging your website as a lead generating machine.
Google ranks websites that they trust. The seach engine is the world wide authority in ranking websites. Google has made numerous changes over the last few years that have made headlines. The objective of all these changes is not to penalize websites and let make Google more money. They insist the objective is to deliver better answers to peoples searches.
Google wants to provide the right answers to peoples search requests. Just because you claim a keyword authority is no longer enough. It takes time for Google to trust your website for the keywords you are pushing. It requires working diligently every week over months to gain the approval of Google as an authority and gain ranking. To maintain that ranking you can't stop because your comeptitors are on your heals trying to topple others and move their web pages up in ranking.
Gaining and maintaining authority with search engines is now a long term process. SEO needs to be a task in your marketing plan and a budgeted item. Adding content that proves your expertise must be done continually. That is why blogs have become a formidable marketing tool.
As you can see from this blog, the answer to "How long does SEO take?" is not as easy as putting in a number of days. If anyone promises to get your search ranking on page 1 in a month ask for details because it won't be what you expect.