PC System requirements for Linux o/s

Have an older pc, 450mhz, 256kRam, 12gb HD, running windows xp pro, an upgrade from 98SE, it works but needs help- bloated registry etc, & i’m tired of farting w/it, so I wonder if this old boat anchor has enough soup to run one of the Linux based o/s that are discussed here? Really dont think I need to just pitch pc out the window, ha ha pitch windows out the window!
I am thinking of formatting HD & installing Linux from a CD that I can order from one of the websites. Then using Firefox, a Linux compatible email client & some other office pgms.
What are system requirements to run Linux o/s, browser & some office type apps? Word, excel, ms project?
Can I run ms office suite w/Linux based o/s?
Bless you all for your advice!