OlD schOoL reLoaded: Linux Loading

hi! i'm planning to rebuild an old mobo, its a sis530 chipset, 128MB RAM, 8MB shared video, ESS  Integrated Sound Chip, 10GB Western Digital HDD, 60x sony cd-rom drive, AT power supply, and running a 500MHz AMD K6-II Proc. it's actually a rebuilt project, if you know what i mean. now, i'm planning to install a non-windows OS for to have a study on Linux System because I have a limited knowledge on these.

Now for my question, which Linux Based system will be the best system to install for begginers? can you name a few for a start? any input is greatly appreciated. thanks a lot!

-j