I'm not an expert on this stuff (thus the quick answers)
but I hope I can help anyway.

> 1) can I boot netbsd off of a firewire drive? or even use
> the firewire drive? firewire cd-rw? Or do I have to install
> it onto the internal hard drive?

I believe NetBSD doesn't support FireWire in any way.  Get the
internal hard drive ready.

> 3) After a great deal of downloading openfirmware docs, faqs,
> etc. I still haven't found a boot command or instructions
> for this particular machine. Nor have I found the partitioning
> program yet in the mac software (reminder, I am a mac neophyte).

What version of the Mac OS are you using?  In version 9 the
partitioning software is called "Drive Setup".  You can also buy
third-party partitioning programs that have more features.
If you are using OS X I can't help you.

Did you get the INSTALL.html file yet?  It contains very detailed
instructions (which you should read over before you actually do
the installation!) as well as information about partitioning
and booting.  It covers 1.5.1 (I doubt 1.5.2 works any differently).

ftp://ftp.NetBSD.ORG/pub/NetBSD/NetBSD-1.5.1/macppc/INSTALL.html

The boot process happens in stages, and each stage can only deal
with certain filesystem types.  INSTALL.html explains that well --
I just wanted to emphasize it.  Here's my current setup:

1.  get into Open Firmware

2.  load bootloader with "boot" command

    boot hd:9,\ofwboot.xcf hd:13

    The "hd:9," specifies the drive and partition.  Your OF will
    tell you what drives you can use:

    dev / ls
    devalias

    but only you know the partition number.  The "\ofwboot.xcf"
    specifies the location of the bootloader.  It must be on a file-
    system that OF can read.

3.  bootloader loads kernel

    The "hd:13" above specifies the location of the kernel.  OF
    just passes everything after "hd:9,\ofwboot.xcf" to the boot-
    loader.  Unfortunately the bootloader's syntax is a bit different
    from OF's (it uses / in pathnames instead of \ for example).
    And the kernel must be on a filesystem that the bootloader can read.

4.  kernel loads everything else

    You can now stop worrying about OF. :)

In order to get all of that working on my machine, I found it was
safest to make sure I could boot from the install CD, then partition
my hard drive/reinstall the MacOS/install the bootloader on an HFS
partition (which all must be done from the MacOS), then boot from
the CD again to run the NetBSD installer.

> 4) I admit that I'm not a forth guru, but even in the open
> firmware, there is no documentation that I have found that
> tells what the valid forth "words" are. Is there a reference
> manual I can get to understand how to poke around a little
> with it? Basic forth I can get at the bookstore, I'm wondering
> about the stuff to read out your machine configuration, build
> a boot string, etc.

See the INSTALL.html file.  Also use the "words" command (you
mentioned a very valuable resource without even knowing it!)
and use "see xxx" to print the definition of word xxx.
Apple has some information on their Web site.  This page links
to Apple:

http://www.netbsd.org/Documentation/Hardware/Machines/Apple/

There are undoubtedly specific books about Open Firmware.
I haven't found any yet myself.

> Thanks in advance. I have probably missed available online
> docs, but have already poked around on the netbsd site quite
> a bit. urls that point to the above info would be greatly
> appreciated, and plain cookbook instructions on getting
> netbsd up and running on this particular system would be
> even nicer.

Once you take the time to explore the NetBSD site, you'll probably
find that it has a lot of information and is very well-organized.
In the left sidebar of the main page, try:

    "Distribution" / "Latest release - 1.5.2"
    "Distribution" / "Supported Hardware"
    "Distribution" / "Software for NetBSD"
    "Support" / "Documentation and FAQs" (and everything on that page)

And in the right sidebar, try:

    "Platforms" / "macppc" (and everything on that page).

Good luck,

-- Derek