I am a sales manager in a retail bakery in Georgia. When I began working for this 30 year old company, no coffee was served. They had a two door cooler with soda, juice, and milk. I couldn't bear the idea of donuts and no coffee, so I proposed adding coffee to our lineup. I knew very little about the coffee industry, and I was fortunate enough to find a roaster and begin brewing decent coffee, instead of using preground packets of coffee. Our coffee sales have increased, and now I am brewing and serving up to 6 or 7 gallons to our customers and our staff. We upgraded our equipment to Fetco recently.
We did not go the barista route, as we didn't have the space or personnel for an espresso bar. Since then, I have developed more and more of a fascination, (no, it's more of an obsession) with great coffee, and have come to the point that I want to open my own coffee shop. I like the coffee business better than the bakery business, I guess.
If you go the barista route, do it right. Training, attention to quality and detail, good equipment. Don't do it halfway. If that seems too big a commitment, maybe start by offering quality, fresh roasted, fresh ground coffee brewed in a quality brewer, served in dispensers that can maintain at least a modicum of freshness. If your customers respond well, you may consider upgrading to a full espresso bar.
Go visit the Hub Coffee Co @ 32 Cheney St. They really know their stuff. I don't know if they do consultation, but they can get you on the right track.