Backing up files before installing Leopard - How?

I'm new, glad to be here.

My question is about backing up files before installing leopard on my powerbook g4. will installing leopard wipe my harddrive completely? and how do i go about saving the many gigs worth of files i have? This is probably a duplicate question so if someone has the patience to answer me or can direct me to previous replies, i'd appreciate it.

Get an external (preferably FireWire) HD, plug it onto the Mac. Boot to the Install CD that came with your Mac.

Open Disk Utility from the Utilities from the Installer. Select the FireWire drive and erase it as an Mac OS Extended Journaled format. Choose Restore. Then select your Internal as the source and the FireWire as the destination. This will make a complete copy of the existing HD. Be sure to get a large enough capacity FireWire drive to do the job.

This can be done with a USB drive, but FireWire has "boot-ability". A feature often overlooked.

Then just use the no OS (10.5) DVD to upgrade the existing HD. If you prefer you can erase and install but upgrading may solve a few hassles. Of course you may also want to verify the data on your FireWire drive before you go ahead and upgrade.

Another option (what I just did this weekend) that you can do is copy all your info to another computer on your network. I have a Windows PC with a 160Gb drive, and shared a folder on that system, then connected to it and copied my files (Music, Pictures, etc) over to it.

It will take longer, especially if you are wireless, but it's a good option if you have the ability.