Hi Mick and welcome to the forum!

The Kindle 3G is a great bit of kit and you can indeed do what you've asked. We have had one for about 18 months and use it regularly on our travels for emails and also basic browsing.

Ours is what now seems to be called the 3G keyboard Kindle and the keyboard is pretty grim! Small, hard plastic keys and a 5 way clickable 'mouse' that make browsing frustrating. It's also very slow to load pages.

But other than the initial purchase its internet use is completely free (so far anyway) and to me that makes it worth the effort - oh, and you can also read books on it

There's an old thread here with more info.