First take some classes in photography at your local community college to learn the fundamentals of exposure and camera control so you can constantly get the proper exposure and composition every time. The reason for this is you want to be able to spend your time interacting and composing the subject, not fooling around trying to "get the camera settings right". You want to get to the point that all the settings on the camera is intuitive and the fastest way to do this is to take a few classes and avoid learning bad habits and the frustration of learning by the "try and fail" method. Even if you had over 20 years experience as a photographer, taking a class in photography every few years is a wonderful experience and can give you a fresh blast of creativity.
Home business or brick and mortar, running a business is the same. You have to deal with the fixed and variable costs as well as the budget for capitalizing your business. You can contact SCORE and they can help you write a business and marketing plan as well as make a P&L spreadsheet so you can determine if your business idea will make enough money to make it worthwhile and not put you further into the red.
First you will want to determine if you have enough of the proper photo equipment to do the job. Do you have a camera system like a 35 mm SLR or DSLR and the lenses you need to shoot babies and pets? If not you have to budget for that. Shooting pets and babies will require a lens like a 24-70 mm f/2.8 and a better than entry level camera body. You will also have to include in your budget lighting (while you can and should use incandescent lamps when shooting products, you will need to use some kind of studio flash system when shooting children and animals). You will also have to include a background stand and a few backgrounds in your budget.
Look here for some ideas for the studio lighting and background packages.
http://www.bhphotovideo.com/c/category/1161/Lighting_Studio.html
