well, the best thing is to practice....lol there is no way to "cheat" a nice braid. Everyone has to start off somewhere! for a french braid in the mane, there are two types, the type that is right on the neck and the type that runs along the bottom of the mane (like video). The one closer to the neck is harder to do properly, and does not stay in that long. Try the style in the video.
For the tail, you can also YouTube it... there are so many videos, and they are much better than typing it out... remember to have a clean and brushed mane and tail to start with and to use small strands for the tail. Other than practice, i can't really recommend much else.... good luck!