Yeah getting into keyword research requires time and will to do it but also most important is experience so you can compare what is too competitive for you. For example what is too competitive for someone for another will maybe be easy, it all depends how good you are in SEO and link building. I usually separate keywords in 3 groups. Of course longtail the easiest, mid tail something that will take some effort and most competitive keyword which is usually the "root" keywords of my site. You can get most links for homepage because it's your domain and all directories and similar things you submit only top level domain, not deep links. For categories (silos) I use mid-tail and for articles/pages I use longtail mostly. So yes, if you have a good SEO process and you know how to do Link Building than you can aim for high search volume keywords but if you are new into this it's better to stick with a lot of longtail keywords. You have to understand that search engines rank pages not sites. So target 1 keyword with 1 page. That will get you the best results because this page will be optimized for that 1 keyword.