CVs are extremely crucial!!
THat is the reflection of ones trueself.. its extremely important to write your cvs correctly.
A good cv is what take a candidate to an interview.. most cases get rejected earlier only
There is no specific or special biodata for sales or finance or marketing. It basically your academic projects or your subject or your work experience which works out as making your cv.
If you have taken relevant subjects of sales and marketing, and have done projects and have relevant sales expererience, then your cv shows the same