I remember just a short few months ago when I first dove into the camera word - words like ISO and shutter spreed were words I had to look up and I knew absolutely nothing. I now find myself in that place again with picking out a flash. I do a lot of indoor shooting in an office building. I own an afterschool program for elementary kids. I find that now I need to purchase a flash because the lighting isnt sufficient but dont know where to turn to. Could someone provide me some basic information like the different types of flash out there?