Where can I learn the not quite basics of baseball?

I played backyard baseball as a kid, but that's about it. I know the basic rules and positions. I dont however, have much of any idea what the role of the individual players is. My sons are absolutely in love with it though. My oldest did a year of tball and is in his second year of coach pitch. My middle one is in his first year of tball. They aren't the greatest at any aspect(except my oldest who can hit anything I pitch at him), but I've got it drilled into them to pay attention and move fast, which is better than most of the kids staring at the ground or picking their noses. I've been asked to be an assistant coach, but I'm not 100% on my knowledge. Specifically, between 1st and 2nd. Where do the players stand, what should they be doing during a play, etc. Things like if a player going to first gets forced out, is getting the ball to second also a forced out or can the runner go back to first, and where should the basemen be standing so they can still catch without being in the way of the runners? A few other questions too. My kids want batting gloves. I don't really think it's worth it because they don't have any calouses to protect. Is it worth getting them some? Same with catchers and pitchers mitts. My oldest loves to play catcher, but rarely catches the pitches. This is mostly because the coaches pitch like shit and the balls are dropping on home plate. He'll be in little league next year, and I think he'll do better as a pitcher because he can throw straight and fast. Does either glove make a difference at their level?