There are very many types (or distributions) of Linux. Popular ones include Ubuntu, SuSE, Fedora, Debian, and many more. Let me know what you are looking for and I can assist you with most questions!
There are many distributions of GNU/Linux such as Suse, Ubuntu and Fedora Core. Personally, I would recommend new GNU/Linux users to start off with the LiveCDs. A LiveCD will allow you to run the OS off the cd without any installation. Knoppix would be a good option. (www.knoppix.org)