looks like a good start starjsjswars - this is great choice of dino!

i don't have any raptor refs at hand, but at the moment the arms look a little long - as you said though, it's at an early stage.

i also think you need to really focus on how the various parts of the body connect. at the moment everything is looking a little stiff and flat - there is very little balance at the moment - for example, how the neck or the tail comes out of the body.

When you look at an organic form you will often see contrasting curves on opposite sides of the contour - where the form will do one thing on one side, it will often do the opposite on the other - not always - but depending on how you deal with / exaggerate / play down these forms will really help bring your model to life and make it seem organic.

sorry for the lengthy post. hope it helps.