I want to share that avoiding competitive keywords is part truth and myth. The truth is when starting a site you will want to avoid them but they should be part of the big picture. The trick is to go for a competitive niche but research and find longtail keywords with little competition and rank on the first page of google for all of them. Once you have established yourself with those keywords and have seen some stability in the serps for an PR update or two you have now established some trust with the search engines. You know you will have the most trust when the search engines have ranked on the first page with especially if most of your backlinks do not have your anchor text. You do not need backlinks with keywords for anchor text to rank well. You will also want to be linking most of your backlinks to your inner pages. Once you are ranking well now is the time to introduce more competitive words. Usually within 6 months to year you can be ranking for very competitive words if you have an aggressive backlinking campaign. Sometimes this can be done in less than 3 months. I also recommend some automated tools and outsourcing. Aggressive does not mean a billion links it means going out and finding dofollow links with good PR on various sites.
In order to get established it is much better to start with long tail keywords once established you can make it more broad but it will still take a lot of time to get decent ranking for a highly competitive term.