[vox-tech] Cloning a drive?

[Paul]

I need to move my desktop from a (full) 10G drive to a (spare) 20G drive.

The ideal results would be copy everything over, then run lilo on the 
new drive, then it would boot up looking just like the old one.

Some googling found me an out of date HOWTO and a few sites with 
instructions that were a little vague, so I thought I would ask the experts.

Has anybody done this?

Is it easy - not to hard - increadibly difficult - don't even think 
about it?

How do I do it - or better yet - a site with almost idiot proof 
instructions.

What are the things that can go wrong?

Thanks, Paul