You might want to look into Overture at Geniesoft.com.
I've tried Sibelius and Finale, both excellent programs and expensive and steep learning curves. Overture is half the price and easy to learn. This is what I now use for a simple lead sheet to large arrangements.
They also have a scaled down version called Scorewriter which I believe is less than a humdred dollar and also very good.

A program like Band-In-A-Box is very good if you want to just push buttons and have the program creat an arrangement for you and good for lead sheets and some orchestration.

Good luck

Peter