You can use a free web based proxy service. These are very easy to use and will anonymize all your web traffic. The proxy works by making the web request for you (from the proxy server), then delivering the web response (html page, images, etc..) back to you.
If you want to mask your traffic at an 'isp' level, you need to use the service over a secure connection (https). HTTPS is HTTP over SSL, so the entire transaction is encrypted.
Other proxy solutions include using a SOCKS/HTTP proxy. You can set your browser to use one of these proxies in the browser settings. Since the proxy tunnel is managed by the browser, its usage is transparent and work better.