How do I share files with a PC running XP?

I wanted to share files between a PC running XP Pro and my Win Laptop through a router with ethernet cables. I tried a lot and lot (have done system restore for 8-10 times in this process) to do this by following the tutorials and guides all over the internet but in vain. I don't wanna mess it up again, so someone please share the exact correct way of doing this.