Is it possible to share my internet from my laptop?

I can connect to the internet from with my ethernet through a broadband connection. I was wondering is it possible to create a wireless network from my laptop that allows other laptops to join and gain access to the internet that im connected to. Ive tried creating an ad hoc thing but it still doesnt work. Is it even possible or do i have to buy a router. If it is possible could you provide a step by step.