I have heard and read about public access WiFi being unsecure. I understand some of this yet some I do not. How risky is it to use public wifi and if I am using a SSL Connection with a website is my data secure?
Public WiFi access is generally regarded as insecure. Because you are sharing access to the network with untrusted users, you cannot guarantee that your data is secured on the network. This applies not only to website, but also email and any other network communication (instant messenger, file transfer, etc).
There are several ways to secure your network communications on a public wireless network. SSL is a good start for securing your web browsing. Using POP3S/IMAPS and SMTPS for your email client will protect your email communications over the network. Many instant messenger clients now have support for SSL in the services they supply. SCP or SFTP can be used to secure file transfers. An ultimate solution would be Virtual Private Networks (VPN) or SSL tunneling of all the network communications to a trusted (private) network so you have less to worry about.
Consider the articles noted in the comments for additional information.