"Be prepared. that's the Boy Scouts' marching song..."

absolutely agree on the first aid course, and be sure it is one oriented toward outdoor situations.

Acquire a reaslistic understanding of the potential hazards you will be facing and take reasonable precautions to prepare for them.

Several times I or someone in the party has tweaked an ankle or knee, so I always have one Ace bandage with me, more typically two. They will help get you to the trail head and on to definitive care. Be sure and tell the good folks in the ER that it only hurts when you laugh.