Serving advice needed :)

[keven01]

Deuce side
First serves: http://www.youtube.com/watch?v=GS4QkWJ5B5w
Second serves: http://www.youtube.com/watch?v=zT08ScysQdk

Ad Side
First serves: http://www.youtube.com/watch?v=-6po7WTJpIY
Second Serves: http://www.youtube.com/watch?v=6L7zQTS592I

Immediate thoughts: I need to load more on my legs, explode up into the ball, and bring my hitting arm up higher.

[SystemicAnomaly]

Only took a quick look at one of the videos. Not bad at all.

Your tossing hand should continue upward after the ball release. you tend to stop it right away and/or pull it down too quickly. Take a look at the pros. After the ball release, the tossing hand keeps moving upward so that the arm assumes a vertical position. This gets your front shoulder higher for a better shoulder tilt for your trophy position.

The extended hand also provides a better reference (measuring too) for your toss. It helps you to better determine the quality and location of your toss. It should also provide a better indication for when you should swing at the ball. Do not pull your extended arm down until your racket head drops from the trophy position down to the scratch position.

[LeeD]

Lookin good...
Only thing I see that is glaring....you are swinging slower on your second serves. Since you add much more spin, you need to swing faster on your second serves because...you can. You can because a spinny serve is led by the leading edge of the frame, so it's not presenting a full face, and it's more aerodynamic.