I like your question. good to see some want to do the right thing. there are areas where Mt. bikers are not seen in the best light and to have your attitude will make a positive impact to our sport. IMBA(as stated above) rules are a good rule of thumb to start.when coming upon hikers/joggers keep in mind, especially if you are approaching from behind them, they will not always hear you so let them know more than once if needed that you are approaching and on which side. to yield the trail,clean up your evidence of being there,and always greet others you see will make a HUGE impact for the good where you go. I read somewhere that if you can leave the trail cleaner than when you came(if you see trash pack it out if you can) also volunteer for trail maintenence when you can.you will love it and the trails benefit from your effort