Need help resizing LVM patition

[Andrew Konosky]

I have two 80gb hard drives, and use one ~35gb LVM physical volume on 
/dev/hda4 and one ~75gb LVM physical volume on /dev/hdb2. My /boot 
partition is /dev/hdb1 in ext3 and my / is mounted on 
VolGroup00/LogVol00 in ext3 also. I want to reduce the 75gb hdb2 to free 
up about 25gb so I can have room to install and try out some other linux 
distros.

I have searched online for insructions, but all I can find is stuff on 
resizing reiser and ext2 partitions. I am not sure if I need to resize 
the LVM voume on hdb2 first, and then the filesystem, or if I do it the 
other way around. What commands do I run to do this?

I want to end up with about 25gb free space to install Debian 3.1 on. 
And also, how do I configure the grub bootloader for Debian? I would 
like to keep Fedora's grub as is, and just add one entry for Debian that 
launches a separate grub menu with Debian and its different kernel 
versions. Would I just install grub on the new partition? What entry do 
I make in Fedora's grub.conf?