Hardware questions

[dfro]

I am trying to instal YDL for the first time.  I am a definite newbie.
I have never even seen a linux box run.  Even so I want in on the Linux
revolution!

I have read some books, read a lot of sites, but I still have many basic
questions which I am having a hard time finding answers to.  I am also
frustrated by how little macs are mentioned in all the How To books that
I have seen so far.

My computer is a 550 Powerbook G4 laptop with a 20 gig hard drive.  I
run Mac OS 9.2.  I would like to run old Mac programs in OS 9.2 or in OS
X's classic mode; and run linux, gradually phasing out my use of Mac OS
and Mac programs all together, if possible.

It seems like laptops and desktops need to be treated differently.  Am I
correct?   One difference seems to be that laptops only can have one
internal hard drive.  Am I correct in stating that you cannot boot Linux
from an external hard drive yet?   Linux will not boot from external usb
and firewire hard drives yet, right?   And because of that, if you want
to run mac and linux, you have to partition your  laptop's hard drive
for mac and linux?
Will Mac boot from and external hard drive?

I have a couple of scenarios I am considering.  Any advice or alternate
scenarios would be greatly appreciated.

1.  Get a new internal hd with YDL and Mac OS X preinstalled.  Remove my
existing hard drive and put it in a firewire external hd craddle.
install the YDL/OSX hard drive.
Does YDL sell internal hard drives for laptops as well as desktops?  Is
there a cost difference?  They do not mention this.  Maybe something in
the specs makes it obvious, but not to me.

2.  Partition my existing hard drive to run YDL and leave Mac OS 9.2
alone.  Do I need a Mac boot CD for this?  I don't think one came with
the computer.  Is there a way of making one from my computer?  I can add
linux partitions without disturbing my mac partitions, correct?

3.Set up an internal linux hd and an external Mac hd.  Would that work
when booting the computer?  These may seem like dumb questions, but this
is all new to me.

4.  Some scenario where I buy OSX and YDL 3.0.1 and install them based
on what I hopefully learn.

Thanks in advance for any advice.
Dave