Getting wireless on my laptop

Hi i just baught a acer aspire 3680-2022 laptop and am trying to get connected to wireless internet. It has a Acer InviLink 802.11b/g Wi-Fi CERTIFIED Wireless Network card. I can connect to a network but cant get on the net. I found out that i need to create an access point. If i buy a wireless router this should set me as an access point right? And then i will be able to get on the net. I have windows vista. Also under my connections i have one that says “free public wifi” is this really free wireless internet? Any help would be appreciated. Thanks