What workout routine will be the best for me?

I am 25 yrs old and I am fairly tiny (5'6, 115lbs), I have decided that I am ok with being skinny now. I have tried since High School to gain weight and have been unsuccessful. So now i just want to tone up and gain some kind of muscle and shape my body through working out. I started working out 2 wks ago. I try and do at least a 20 minute workout everyday except Sun alternating between morning workouts and nightly workouts. I have been working mainly on my arms and shoulders with 3 and 5lbs dumbells, My , thighs, and my waist. I sometimes workout with the programs on excercise TV, but i would like to customize a workout to do on my own also. Any suggestions on what work out will be most effective for me and what kind of results should i expect and when should i start seeing them?