Sounds like you have gingivitis starting.  Start with a soft toothbrush, you dont need one of the damn bristle broom ones.  Use a good toothpaste...Paradontax is made for gum issues like that and isnt too expensive.  You can swish LOW concentration peroxide a few times a week and that'll help the gingivitis...tastes like ass though. A like someone above said, use floss.  Other than that,  a deep scale cleaning helps a lot but it isnt fun. Hope it helps.