Linux Distro Watch has been around for some years now and there's plenty of Linux operating systems available to download and try.
http://distrowatch.com
If you're new to Linux I would suggest reading all documentation first from the developers websites. Some involve partitioning your hard drive and I would not recommend this for beginners but if you've had some experience at this then you'll be right. Some of them will load from a CD or flash drive which is great if you would like to try them out. They range is size from very small, compact and limited to the very large, full blown operating system with all the bells and whistles.
