I suggest that the question should be if Twitter is the right first step. One common position is that one should start using Twitter to build on an existing audience platform or brand that is well defined and already marketed. I suggest you look in at LinkedIN first, join groups in your expertise/product/solution area and build your brand as the go-to-person or company for that subject. Then begin to crosspollinate by tweeting your blog posts or group answers with the hashtags that matter to your community.

When I started on Twitter I slowly built up a brand and as I found that my interests were split in a variety of areas, I created a few twitter accounts as my followers would drop depending on my subject focus. This allowed my various brands to continue to build as I answered questions on innovation, cloud computing or entrepreneurship by tweeting from conferences, retweeting blog posts/interviews, and engaging in twitter chats from big research firms, subject matter experts or media outlets.

My advice is to focus your time as Twitter does take time to build credibility in your field and you may be better served by joining portals or groups in your subject area and as previous experts have noted, get engaged in the discussion and offer support.