Ok, thinking about it for a moment, I think I know where your frustration lies actually. I looked at the thread quoted above, and while this is very clear to people who have already rooted, it might seem like one, long, muddled string of hazy comments.
So, lets break it down.
To root, you need to break it down in steps.
For example, step 1 - Setting up Android SDK - HAS to be done, period. It is always the first step, and gets your PC/Mac ready to connect the Nexus One in such a way that you can run commands on it. Do that first. Breathe... and stop after that. It is the most difficult one! But HAS to be done...
Ok, step 2 to 6 are next. One by one... follow these instructions.
Step 2 gets your Nexus One ready to receive the commands from your PC, that you set up in step 1. Up to now, you can not changed anything yet. You can still go back... no panic, no sweat.
Step 3. Here, you unlock the bootloader. Why is that? It changes your Nexus' virginity forever - whoo hoo, that is a bit step!
That's it for now... it's getting late. Hope that helps... point is, break it down in steps, and make sure you know what is happening, and it won't be difficult at all. Good luck!
EDIT: Ok, I see we crossposted. Sorry sir, I can't say I like you. No more help from me I'm afraid
I thought you genuinely asked for help, but instead, you came with your boxing gloves on. I shall never respond to your posts ever again.