i am trying to animate a character model and am having issue with floating characters.

i have noticed since i have starting using unity and was experimenting with it that every time i animate something there is a delay in the start and finish of the animation. i have tried tinkering with them and have had a little success with reeling in the from walk to idle gap, but the form idle to walk does not seem to get better and still seems like my character is gliding along the floor before the animation finally starts a walking gesture. can someone point me to some good tutorials or offer advice on how to clean up the transition times between animations? thanks