Goa is one of the best beach I have visited.
We went in the month of october on an extebded weeked and trust me it the best time to be there. I would recommend you going there with a bunch cool fun-lovin friends.
Must do in goa:
Vist the dudhsagar falls
Hire a bike and ride through the streets
Sun bath in the awesome beaches
Water sports
Boozing ofcourse
Visit the night clubs
Buy cashews to treat your family.:)
Things to avoid:
Driving a two wheeler without helmet or license
Going to the aguada fort. Its a complete waste of time and energy.