How do I move my character properly?

Hi, i've got a problem. I have created an character with few animations in blender (like walk, crouch, etc.) ,but when are you doing something with your hands(like aim) and with your legs (like walk) and then are you doing the same thing with legs (like wlak, but another with your hands (like reloading),you would have to make lots of animations. So, i decided to split the character in half and do the animation only for half, but blender assigned some random activity to rest of the character, I think I red something about seting the weight for animation for only part of the character, is it possible?

PS: Sorry for bad english,I am from Czech Republic.