I'm a small business owner, and I have a nationally ranked website for some of my keywords(20% #1, 10% page 1, the rest not SEO yet). The SEO company I used before is getting so expensive that I couldn't afford, so I'm thinking of doing some SEO myself since I have decent knowledge with SEO. I love all the BH stuff, I'm just very hesitant to use it to my business site since my whole online business depends on it. My KW are medium+. I know I would probably need PBN to rank some KW if not all. For link building part, I was wondering what would be a safe approach for me to build links? Is it starting with web 2.0, or guest posting, maybe PR? I'm going to outsource some of the work like content building, but what should I put the most effort in? What should I avoid doing to minimize the chance of getting penalized? Thank you!