Welcome, I'm glad you are seeking advice first. Do some research first, visit you local library or buy a book. Probably the first thing will be to define what you want to grow. Maples, Pines or Junipers are ill suited to indoor culture. Conversely, Ficus and Schefflera will not tolerate winter temperatures in many areas. Where are you located?
I mainly concentrate on temperate/outdoor species, I feel it is easier/better to allow nature to provide much of the trees requirements. Even tropical species are usually kept outside during the summer. It takes a lot of the burden from the grower. Inside will require more from you in the way of lighting especially but also humidity can be a problem.
Bear in mind that since bonsai are living things they will require daily care for large parts of the year. Depending upon your location and your decision indoor/outdoor they may require daily care year-round. Much of the time this is simply monitoring and watering but you cannot simply forget about them for days on end. You can easily lose years worth of work over a careless weekend.
Here are some links that might help: