New Win 8 Install

I have a desktop PC which I built myself about 5 years ago: XP Home, ASUS P5K3 motherboard, Intel Core Duo CPU E6850 @ 3.00 GHz, 2.00 GB RAM (unbuffered non-ECC DDR3 DIMMs) with a 260GB HD. System has performed flawlessly since then

I'm thinking to upgrade to Windows 8 and planning to upgrade the RAM to 8GB (either 4x2GB or 2x4GB modules) Motherboard supports up to 8GB RAM

Do you think my machine is a good one to run Windows 8 after the memory upgrade?

When I install Windows 8 is it going to erase my HD or it will just replace the XP Home? I don’t want to keep the XP Home

Any good site to familiarize myself with the new OS with tips / tricks?

Any other suggestions before I proceed?