My main drive died on me recently and now I have to reinstall. No big deal but most of my data is on a different drive that's been partitioned. Here's the output from mount

/dev/hdb2 on /home type reiserfs (rw)
/dev/hdb3 on /mp3 type reiserfs (rw)
/dev/hdb4 on /store type reiserfs (rw)
/dev/hda3 on /tmp type reiserfs (rw)
/dev/hdb1 on /usr type reiserfs (rw)

Now the main directories that I'm worried about are pretty obvious. /home, /store, and /mp3. All other directories were on the drive that died.

This is where I'm a little lost though. During the reinstallation passing the mount points to the second drive same as I did when I installed will not destroy the data in those partitions, as long as I tell it not to format it correct?

Yes correct. Only point is when you set the new /home and create new users, the installer will see the already existing /home dir and ask you what to do. Simplest way is to set different names and just transfer files to the new one.
Maybe you wanna consider backing up with a linux livecd, for instance, before going through this.

Good luck! Keep us posted.