Rank n' Bank Advice...

So I've decided to try to rank n' bank some sites. I have reasonable SEO and some local SEO experience. My goal is to rank 2-3 websites in different niches on Google. Then monetize.

I have a couple of questions with regards to Rank n' Bank strategy though.

I bought a domain for a management consultancy website I'm going to build. But I'm wondering whether I can produce enough content in this field to rank and convert visitors.

Are you better off sticking to high-value items like management consultancy or going for something low-value like electronics repair? An area in which I'm more familiar.

Does anyone have any general advice for me? Rank n' Bank strategies perhaps?