How do I go about getting my very gentle dog to be able to visit sick children?

Hi Marcello, You're dog sounds like she definitely has the temperament for therapy dog work. To begin, make sure she is used to being around all kinds of people, dogs, sounds, noises, etc. With a beagle, be especially sure she will pay attention to you with food around. They do like to think with their noses! If she is comfortable in different environments, then go for it! Google Therapy Dogs International or Delta Society and check out their requirements. Join a dog club in your area to take some obedience cles that will help you develop a great sit, stay, come, etc. Teach her to stay with other people quietly while you are out of sight. Introduce her to people in wheelchairs, with walkers. And teach her to "Leave It!" That's very important, because you want to work in hospitals where pills and other dangerous items can be on the floor. The TDI and Delta websites will have a list of "evaluators" that you can contact to find out when you could take a test. It will also have a description of what to expect. With TDI, you can earn your Canine Good Citizen certificate at the same time you take their test. Not sure about Delta. Once you p, you will want to join a chapter group of whichever organization you join, so you can do visits with others and learn what to watch for to protect your girl and be successful. Good luck, and I know you're going to enjoy your experiences.